Hi Mike,
... By the way, the reason I've ordered a second HD is because the first pair seems to be exhibiting less than pin-perfect focussing in the left scope. After testing, the weaker of the two units will be returned to the supplier as a "manufacturer's defective unit".
Cheers,
Robert
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Well folks, the replacement 10x32 unit arrived and it is, indeed, a cherry specimen. Tack sharp in both barrels (the first unit exhibited less than perfect focus in the left barrel), and an even better feel to the focus drive. So, my first ammended conclusion is that variability between individuals of a kind may exceed variation between kinds, i.e., between a given pre-HD and a given HD of the same configuration.
Following is my edited summary, ammended as noted from post #196 (this thread, above):
10x32 HD vs. 10x32 pre-HD:
Focus Knob: I never had a focus mechanism issues with my original Ultravids except that after a long period of use in very warm weather there might be a touch of play in the knob before engaging the gear drive. This would invariably go away after the binoculars returned to more normal working temperatures, and was never more than a theoretical annoyance as function was never impaired. So it remains to be seen whether or not the HD will perform better under those conditions, or if it may prove to be more durable over time (My 8x42 Ultravid BLs went in for a focus knob tune-up and all is now well. My 8/12x42 Duovids have always been smooth as silk and totally responsive). Suffice it to say, the HD focus is fine, even great, but I was fortunate enough to find the older version equally fine, so no real gains or losses there for me except for the as yet undetermined durability-over-time factor.
Addendum: The 2nd HD Unit has a clearly superior feel to the focus, more apt of the "improvement descriptions" cited in the Leica literature.
Brightness: Here's the greater surprise - I can tell no difference whatsover. Both are outstanding, but one would have expected the HD to be visibly more so. It is not.
Addendum: Once again, the 2nd unit is noticeably, though marginally, brighter under extreme conditions. Colors are a touch more brilliant as well - they seem to "pop", as Arthur Pinewood suggested they might in post #200, above (thanks for the "heads-up" tip, Arthur).
CA: Under extreme conditions (strong hazy backlight) both the HD and pre-HD models exhibit an insignificant (to me) amount of CA. When visible, it is limited to the extreme edges of the view and manifested as a thin violet profile behind the subject. There was no discernible difference between the HD and pre-HD models to my eye.
AquaDura Coatings: I suspect this may be the single most significant "improvement". I'm not about to splatter mud and grease on either to see which one cleans up faster - but there is some real peace of mind knowing that the HD will require cleaning less often, and therefore be less prone to the wear and tear of routine cleaning.
Addendum: I had an unintentional chance to check out this feature late yesterday. In a successful pursuit of a life tick, (a Bohemian Waxwing in Seattle), I was caught in a mid-winter squall. Making little attempt to shield the waterproof instrument from a good test-soaking I returned to the comfort of my vehicle and was happy to discover that a quick flick of my bins was all that was necessary to remove almost all of the water droplets from lens surfaces. A few good blasts with the rocket blower accomplished the rest, without ever having to resort to physically wiping the lenses dry. There was some momentary fogging on the outside objective lens surface (normal even in "anti-fogging" bins), but nothing internally. All glass surfaces dried clean, without spotting or streaking.
The new HDs are slick, make no mistake about it. I just wish the "wow factor" was demonstrably higher in comparison with my older model. I'm happy to have replaced my favorite and most heavilly used configuration, but will not be replacing any of the remaining sizes in my possession.
Addendum: OK, I admit it, there is a bit of a "wow factor" in the second HD unit. Still, only when tripod mounted and compared side-by-side in same time scrutiny.
All in all -- well worth the money, at least the US prices. But if you've already got a working pair of "older" Ultravids there is absolutely no reason to "trade up". In fact, for those of you who would like a new Leica my advice to you would be to get one of the remaining pre-HD models from existing (and dwindling) inventory, and save yourself a few hundred dollars for what is, performance-wise, essentially the same binocular.
Addendum: I'd hold with that conclusion, especially considering that the remaining preHDs will be delivered with Leica's previous, and far superior, Lifetime Passport Warranty. The new HD warranty is for a scant 10 years, although it does seem to be a good risk on such a well-built tool.
In closing, I hope this was helpful to any and all considering an HD purchase, particularly those of you in possesion of the already superb pre-HD Ultravids. I'll be keeping my pre-HDs as a back-up, and because of the superior lifetime warranty, so if any of you have specific comparative questions then don't hesitate to inquire.
Cheers,
Robert / Seattle