I use a Yashica D to pretty good results, but I've noticed the edge definition on Rolleis to be much more contrasty. Don't get me wrong, I enjoy my Yashica, but it's definitely time for me to upgrade. Wide open, the Yashica D can be very swirly and that's not a look I'm into.
TLRs have been my first foray into medium format cameras and I'm enjoying them a lot. I used a Lubitel for a little while, but kind of found it to be horrible. Thankfully, I didn't spend $300+ on a Lomography one. But the Yashica D is around the size of a Hasselblad, maybe smaller, and fits in my Think Tank Retrospective 5 perfectly.
Here's a quick photo from my test roll. http://www.flickr.com/photos/kchoquette/8751102862/