I have a bike built on a 52cm Mark V frame. It's a nice enough frame for the price.

The one complaint I have, though, is that the chainstays don't have any shaping near the bottom bracket to provide clearance for the chainrings.

I originally attempted to put my 48T ring on the frame, but needed to use a relatively wide BB to prevent the ring from grinding the chainstays. Of course, once you start using the wider bottom bracket the chainline starts getting pretty questionable. In the end I used a 42T ring and a smaller cog in the back, which fits pretty well with a 103mm bottom bracket, and keeps a nice chainline.

Despite this one issue, it's a pretty solid frame, and I enjoy riding it.