Hi Paul. I use a WLF. I'm on the lookout for a 90degree pentaprism for those rare moments when I could do with eye level shooting. But nothing beats a good WLF on a 6x6, 97% coverage and very bright, its a dream.
Ah, bright is a key then. My Yashica A is not bright, even with a cloth over my head at mid-day. I can focus it well in the middle but i simply cannot see clearly edge to edge; ergo, I'm having trouble composing. You keep up this fine work ...