Although I'm not 100% satisfied with the way I modified the 60cm abdomen I put on my new 50cm girl from Obitsu, it works and I think it's valid to do a picture comparison. I will be buying another 60cm abdomen, and re-doing the modification (and not cutting off anything like as much vinyl), but unless you look specifically, you can't see anything wrong. So, here's my Shion vs the standard 50cm bodyset.
Update : I linked to an imaged of a Yamato VMF50 Type D earlier, and that link didn't work, so I have updated my picture with the Type D for comparison and a rear view of my own girl.
The larger bust is a huge improvement over the default, and without the modified abdomen, I think it might actually overpower the thin default abdomen. It's not quite a VMF50 from Yamato, but she's definitely got something.
The thighs on the 50cm are actually much better sculpted than I anticipated, they have some real shape to them. Personally, I find the additional curves of the large bust and 60cm abdomen balance nicely, and compare favorably to the Yamato body set, it's most definitely an improvement over the original - IMHO.