My Leica rangefinders come built in both my 8x and 10x Geovids, but as far as their rangefinders capabilities and/or attributes, they are very clear, accurate and I've ranged several 1,300+ yard objects when necessary. Prior to purchasing my Geovids, I owned 2 Leica bino's and 2 of the Leica 1200 rangefinders. Again, flawless functioning rangefinders for several years of lots of use. Amazing battery life, as well. As an aside......selling the 2 bino's and 2 RF's and now only having to carry the Geovid and getting the same benefit of good glass and range finding ability all in one package, absolutely the best move that I ever made.
Rangefinders, in general, can save alot of boot leather, hunting time and sweat over the years and are as worthwhile and useful as any hunting accessory that's available to us........IMHO.