Oh, most definitely! The adapter is fiddly, sort of a pain in the tuchus if you know what I mean. Most Yashica 635's had the three-element Yashicor lenses, not the four-element Tessar-clone Yashinon (but some definitely did). The Yashicor is soft - I think pleasantly so. With 35mm film, it becomes a very nice 80mm f3.5 portrait lens - very soft, yet not too soft - the 35mm is right out of the middle of the lens - the meat, so to speak. And the 35mm kit places the rectangular frame in portrait orientation, so you don't have to go through the ugly contortions that made certain most TLRs would always be 6x6 format - no one likes laying on their side to get a shot.
I run a roll through mine every so often - it has some advantages, but admittedly not many.
Immanentizing the eschaton since 1987.