I own a pair of the swaro slc 10x 42s. I ran the biggest vortex razor spotter for years, it definitely got the job done. The reason I sold it, and started looking into kowa and swaro was the dusk and dawn glassing improvements with the higher end glass. I bought the kowa 99S after speaking to a few guys with lots of experience with kowa and swaro spotters. A lot of guys preferred the kowa spotter over the swaros, and they are a couple hundred bucks cheaper.