I run mostly #110s for mink using blind sets. I haven't had a problem stablizing the round models any more than a square model does (a few sticks, or a commercial stabilizer work equally well). They definitely seem to fit certain "holes" better, but I haven't found this to be an advantage over traditional square models.
R.C. from this end of our state sells some modification kits for extending the jaw width (superbears) on #330s, and has had some success with those on larger beaver runs and gives a more wider opening through the trap and seems to point to less turn aways. This model still incorporates the traditional square opening, just a much larger version demensionally.
I've used modified #220s with bent #330 triggers to accomplish a similar feat for rats but on a smaller scale. Some of our ponds around here are very soft-bottomed and the runs tend to get "large" over time, and this modified #220 fits much better than a little #110 does. Again, still using a stock square model.
I think the round jawed model would also work well here...but it wouldn't necessarily be at an advantage over a different body grip model. Sometimes just moving up to a larger body grip model covers the odd situation just as well for me.
I do like the quality of the RBGs I have, they are a decent trap. But I wouldn't turn down a better cash deal on decent square-jawed models myself simply because I haven't found either one to be that much advantagious over the other in the field.
Jim-NE
