I've a 135mm f4.5 Yamasaki Congo lens in a Seiko shutter. It's a good 'press type' lens and I use it handheld on a 4x5 crown. It's sharp and has great contrast. I've a shot of a lake focused at infinity and the very edges of the negative are a little soft however. I received the lens for free and am happy with it. If I were paying for a new lens I might go for something else (and probably not a 135mm..)
The commercial-ektar type ones do look very nice though. And the soft focus lens is interesting..