Outstanding build quality and exceptionally compact
Incredible tactile feel
Possibly the best dioptre out there
Outstanding objective covers
Bright, sharp images
Slightly more CA than comparable alphas
Slightly narrower FOV
Slightly firm focus
The elegant Leica Ultravid HD Plus 10x42 is the most compact of the 42mm holy trinity (Leica, Zeiss, Swarovski) Alphas. Feeling more like a 32mm in hand, they are very bright, sharp and an absolute pleasure to hold.
Leica have possibly the best build quality of any brand, and these are no exception. They have a fantastic central dioptre (the best I've ever seen), excellent removal flip-down objective covers, solid eyecups, and a view only the very best can match.
Compared to the Zeiss SF or Swarovski NL, the Ultravid HD+ have a slightly narrower field of view and have a bit more chromatic aberration. They also do not feature a field flattener like the newer Noctivids. However they have superb light transmission, outstanding contrast, a brilliant tactile feel, and are unique in their compactness.