What a brilliant weekend here in DC area and what a wonderful companion is the 10x54 HT on days like this in the nation's capitol.
I am continuously impressed with the 10x54 HT's brilliant picture -- it's lively, vibrant, life-like, razor-sharp, with very neutral colors. 10x is much easier to hold steady than I thought. Not much harder than 8x42 but the trade off is definitely worth in terms of more resolution. It just reaches farther out than an 8x.
I wish the eyecups had more tension or click-stops. Not sure about the non-lockable diopter knob. It hasn't given me any issues.
Later on I did some birding in a more rural area. It's far easier to ID with 10x than with 8x. However, 10x54 HT feels twice as heavy as a compact 8x42 model.