I just purchased a Boberg XRS-9 Platinum. It was slightly used - I believe it had one box of ammo shot through it. I have not had the opportunity to shoot it yet.
I have disassembled the gun several times (just field strip, not a full disassembly). I am still learning the function of each of the parts. First, let me tell you, this gun is an extremely well made, complex little machine. There is almost nothing conventional about this gun. It is all hand fitted. Some of the parts are factory polished, which makes the dao trigger exceptionally smooth.
Frankly, I don't know how Boberg is manufacturing these guns and leaving room for profit. The XR9-S is substantially smaller than my Ruger LC9 and capable of handling +P 9mm (and apparently even +P+, though not recommended) and holds 8 rounds.
You must used ammo that is crimped - READ the recommended ammo list; there are plenty of inexpensive ammo brands that can be used.
I also considered the Rohbaugh R9, but chose the Boberg for a number of reasons. When I have the opportunity to shoot it, I'll give a range report.