The Q3TR has a shorter knob on the clamp and it has a straight instead of beveled scale on the panning base. If you do a search, a couple of guys here have done a review on them complete with pictures.
The ballhead is not on the markinsamerica website, but you apparently can get it by emailing them - it is available.
I think the only issue (and it was also discussed here in the threads I saw) was that because of the knob placement on the ballhead body, if you wanted the legs to close fully (with the ballhead inside) you needed to extend one of the legs by a quarter inch or so to accomodate the panning knob, if I recall correctly. Looked like a very nice package.
J.