I was also impressed that RHA had interest in the fit discussions here, so I emailed the address listed above that they gave. They did reply. Basically, they gave me a link to the Comply tip site, and said that was all they could suggest (I tried this, didn't do the trick...they actually put foam tips in with the iem's). I get a decent fit with one of the enclosed tips, but it is very tentative, seal breaks if I make any sudden (or not so sudden) move.
As far as sound goes...these are indeed very nice, especially for the price. I did get a request on the Discovery thread to compare them to the Sony XBA-3 and the Monster Gratitude, both of which I like very much. IMO, the RHA beats them in soundstage width, openness/space between instruments, has a good bass. Overall, though, I like both the others better; they put more "meat" on the instruments, detail better, definitely fit/seal better (I know, the sound may be due to fit on the RHA, but I try to do comparisons with the best seal I can manage, even holding the tips in place by hand some of the time). YMMV, lots of people think they are the best thing since PBJ (and, I do like them, definitely fine performers for the price), just my $0.02