I just window-shopped some LPVOs in a local gun store that had some that weren't the high dollar stuff. Specifically, they had a Firefield 1-6x24 and a Firefield 1-10x24, both second focal plane.
I did not attempt to adjust the oculars on either one, which might have helped somewhat. The 1-6x was okay-ish at 1x, though nothing was quite in focus at inside-the-room distances. Maybe changing the diopter might have helped. At 6x everything in the room was so out of focus as to be essentially unusable but looking outside through the window it seemed okay. At 1x if it was not true 1x it was at least close, which surprised me.
The 1-10x, on the other hand, oh boy. At 1x it was much more out of focus than the 1-6x was, with very noticeable fisheye distortion and a ring of increased blur all the way around. It was immediately extremely noticeable and distracting. Just thinking about it gives me a whanging headache hours later. If the adjustable ocular allows for me to see through it and see things in focus it would be tolerable at 1x, but only just. At 10x outside, through the window, it was considerably better at distance than the 6x. But inside the room at 10x it was unusable. And inside the room at 1x, it was still so blurry that I'm still not exactly certain whether it was close to true 1x or not. The blur and fisheye distortion made it impossible for me to tell how far off it really was. Maybe on a rifle it would have been different. I'd have been able to hold it relatively steady and use a consistent cheek weld. But just holding it in my hand and looking across the shop with it, holy shit. Irons would have been decisively better. Maybe changing the diopter would help, or not, but it was pretty bad.
No doubt this isn't going to come as a surprise to anyone who might be reading this. Cheap Chinese LPVOs aren't as good at being red dots as a red dot is. I didn't expect the 1x on that 1-10x to be as bad as it was, but maybe for whatever reason the adjustable ocular was cranked all the way to one side. Or maybe it wasn't.
I went into this knowing already that there are tradeoffs with everything here. The laws of physics make it unavoidable. There isn't any "best," there's just better for one use case or another.
https://youtu.be/HbKYBVEYpfk goes into a lot of depth. I watched it before but didn't fully understand everything he was saying. The gist seems to be, though:
An LPVO isn't as good as being a red dot as a real red dot is for close-in work, just as a red dot with a magnifier is a shitty substitute for a magnifying scope when you need to do scope stuff. An LPVO isn't as good at being a long range scope as a high-magnification scope with an adjustable objective, either, but it can kinda sorta work for both close in and long distance, well enough that you can train with it and become proficient with it in both modes. This is why LPVOs exist, and why they're decisively better than sticking a pistol red dot on top of a 4-16x target scope, or a red dot and a magnifier.
He also says that the more magnification the LPVO has at max, the worse its 1x is going to be. "Worse" means smaller eyebox, less forgiving eye relief, more distortion, worse focus away from the center of what you see. This is why a 1-10x scope is going to be worse at 1x than a 1-4x scope. This is true even with the high-dollar stuff that costs four figures. They have to make engineering compromises to keep the scope usable at maximum magnification. They could build a 1-10x scope with huge eyebox, extremely forgiving eye relief, perfect true 1x, no distortion, perfect edge to edge clarity, and on 10x it'd be absolutely unusable, even with the most expensive German glass lenses, even with First World care and quality manufacture. There is no way around this. It's physics. The 1x is going to be mediocre at best because the only alternative is to make the scope useless at the top of its magnification range.
There is currently a fad for first-focal-plane scopes designed around keeping a rangefinding/bullet drop compensating reticle functional and usable across the full range of magnification instead of just at max, or, worse, at some arbitrary point in the middle where the optics maker helpfully puts an asterisk on the power adjustment ring--or doesn't. All else being equal a first focal plane scope is going to be worse at 1x than a second focal plane scope. Its eyebox will be smaller, its eye relief will be less forgiving, it will be more distorted, it will have less edge-to-edge clarity, it will be less likely to be anywhere near really 1x when the markings on the ring say it's 1x.
Oh, and I also really, really, really dislike the reticle in the Firefield scopes. I understand what they were trying to do. It's a second focal plane bullet drop compensating reticle. It is designed with the assumption that it's going to be used on a flattop AR15, with its center axis 2.7" above the bore axis exactly, neither higher nor lower. The markings for various ranges on it were set up with the assumption that it's going to be used on a flattop M4 loaded with M855 Ball, a boattailed spitzer bullet with G7 BC of 0.151 at 2840 ft/sec. Any deviation from any of this--muzzle velocity, ballistic coefficient, sight height--and it goes completely to shit and becomes worthless. It is, like almost all of them, also designed to be zeroed at 100 yards, which drives me out of my mind. It's 5.56mm, and even from an M4 if you're zeroing an optic for a far zero closer than 300 meters you're doing it wrong. Also if your ranges aren't in meters you're doing it wrong, and if your reticle dimensions and adjustments aren't in mrad you're doing it wrong. Yes, 5.56mm zeroed at 300 meters it will hit a few inches high in closer, but not enough to make a difference when the task to be accomplished is fast shots at center mass under enormous time pressure. Deer hunters zero the pre-64 Winchester Model 70 at 100 yards, if they even bother zeroing the rifle, if the rifle has even been fired since Grandpa bought it at Kresge's in 1958. They do not make use of the full capability of the cartridge, in part because they are mostly hunting in thick brush country and may well take a shot at powder burn distance (speaking of a use case for LPVOs), in part because an awful lot of them don't know any better. And a significant number of them only bought the gun and the orange vest as props--they're just going "up north" to sit in a shack for a week and get drunk with their buddies, away from their wives, and nobody's getting the gun out of the trunk at all.
...but to get back on track, goofy rangefinding reticles designed by the marketing department ("It needs to look more sci-fi and military! Put more gubbins on it! Can you make them change color and blink?"), or by some bored intern who doodled something in MS Paint, that he half-remembers seeing in a video game years ago, and sent to production with no notes about dimensions or angular subtensions, are par for the course, and result in fun stuff like "mil dot" reticles where an area ten "mils" across is five feet across at 25 yards instead of 9". This is why I like second focal plane and simple reticles. The LPVO is going to be used on 1x like a red dot 90%+ of the time, so please don't distract me or slow me down by trying to make it look like the HUD gunsight of a jet fighter.
And after all this I'm still window-shopping cheap airsoft LPVOs on Amazon, eBay, and, saints preserve us all, AliExpress. Send help.