I was also at the last Birdfair and had a good look over four of the sub-alphas I was most interested in, with my own 10x40 Dialyt (P model) as a reference. I tried the Canon first, then the Meopta, then the Conquest and HG from the big tent before returning to the Meopta and Canon again. I'd intended to post a comparison between them on the Birdfair thread (on which I'd already noted my impressions of the Canon and the Meopta), but seeing that it's now been some time, this is as good as anywhere, I suppose.
Some general comments regarding this group - I thought they were all really good (as they ought to be given their price points), and if I turned up at a birding lodge without binoculars I'd be delighted to be given any of these as a loaner. Each of them has some great qualities and you do get the impression this is a very competitive corner of the market. They are all better than the P model 10x40 Dialyt - all are slightly, but noticeably, sharper at distance - both on axis and at the edge - and show more detail at distance; the "at distance" bit being one of the key things I look for, in part because so much of my observations (especially with 10x) are from a good way away. They are all slightly, but again noticeably, brighter, and colour rendition is more natural.
Meostar 10x42 HD - this was arguably the one that felt the nicest in the hand; compact, solid, with the highest perceived build quality. All four deliver a really good image but the Meostar, I think, offers the most alpha-like image of them all, which is pretty high praise in my book. I did however think it was a little more finicky in terms of eye placement than the others, reminding me a little of the 8x32 FL, a binocular which is so good when you've got it right that you know right away when it isn't. Field of view is also not as good as its competition, though mitigated considerably by good edge performance and being able to get my eyes up close (moving the field stop a long way out) without blackouts.
Conquest 10x42 - I tried this at two Birdfairs and was really impressed both times. Well put together, like the Meostar easy to hold steady, and offers a really good image, bright and very sharp. It's a really formidable package and all things considered is probably the best binocular short of an alpha that I've tried thus far. Highly recommended.
Monarch 10x42 HG - This binocular ticks a lot of boxes - wide field of view, field flatteners for edge performance, light weight, easy handling. The field of view and good edge performance makes it a really useful birding tool, but the image it presents is a little more utilitarian than the others. My impression was that the others were a little brighter (which could be the result of eg. baffling or colour balance as opposed to actual light transmission), a little cleaner and possibly just a little sharper on axis. I could see this binocular working really well under bright Spanish sunlight though, so definitely worth a try - they all are really.
Canon 10x42 IS-L - the odd man out of the four. It's big, heavy and doesn't handle like an orthodox binocular. Even without the image stabilization engaged it's fully competitive with the others image-wise, though far behind ergonomically. But press the magic button, and the absolute steadiness and lack of wobble propels it ahead of not only the sub-alphas but the actual ones too. I appreciate the great majority of birders, and even 10x users, get by perfectly well without image stabilization, but the smaller and further away the target, the greater the advantage IS offers. This is the least impressive binocular of the four in terms of ergonomics and build quality but is the one that best suits my own birding, and which I would (albeit reluctantly) choose for myself.
Regards,
patudo