I have had my XR9-S for about a month now. I went on the pre-order list Sept/2011, got my purchase authorization email April/2012 and had my pistol 2 weeks later. My serial # is 379.
I have about 300 rounds of 9 mm ammo through it so far (115 to 147 gr. with +P in the 115 and 124 gr). and can give you the following impressions:
Fit and finish are superb. No visible tool marks on any surface inside or out. All materials used seem to be top shelf. Operation is smooth with minimal play in all moving parts.
The XR9-S is a very small, light weight pistol that's quite slim and smooth with nothing to snag on clothing. It is almost 2" shorter than my Colt Cobra and smaller in all other dimension as well. The grip is a generous 2 finger grip with the pinky finger under the base. I can almost get a full grip on it but it's more comfortable with the pinky under. The magazines are very small for the 7 rounds they hold. This is due to the lack of a follower. Round # 7 rests directly on the mag spring. I found it carries well in a Remora pocket holster (Remora actually makes a holster specific to this gun) in khakis or jeans in the front pocket.
I was also able to modify a leather Safariland .38 cal. dump pouch that I got at the last gun show for $ 10.00 into a perfect magazine pouch by wetting and stretching the flap about 1/3". Then removing the plastic liner and cutting it to 1/2 size, beveling it and re inserting it into the bottom of the pouch. I carry it flap up, upside down for a dump pouch but perfect as a magazine pouch.
The DAO trigger has the weight, length of pull and reset that feels sort of between a factory S&W K frame and a tuned J frame. It's very smooth with no stacking and a clean break with just the slightest overtravel after a pull of about 7 lbs.
The XR9-S is very accurate and shootable. Offhand I can keep all 8 rounds on a 12" target at 50 yds with 5 shots in the black, one of which hit the bull. I also had no problem dancing a 1 liter soda bottle around the 50 yd. berm hitting it most of the time and missing by scant inches when I didn't . At 10 yd. it's 8 rounds into one ragged hole.
I found that while the trigger pull and reset are long compared to some semi auto pistols, the low recoil and extremely fast recovery allows for fast accurate shooting.
Thanks to the feed mechanism, rotating bolt and grip design, the recoil is very modest. The best comparison I can give is that it feels very much like an H&K P7. I have shot over 100 rounds at a sitting with the XR9 with no discomfort.
There is no last round hold open. When you consider the operating system this makes sense. So, just like a revolver, when you are out of ammo it lets you know by ceasing to make loud noises when the trigger is pulled. However, after your 8 shots you have a faster reload than a revolver.
This pistol is overall very reliable. I have had only 1 FTF in 300 rounds and that was deliberately induced. To whit, this feed mechanism can suffer a type of jam similar to the kind sometimes experienced in ultra light weight .357 Magnum small revolvers (where a bullet "prairie dogs" and ties up the cylinder. In the XR9, if the cartridge does not have a proper crimp, the bullet can separate from the case when it's pulled from the magazine. This will leave a case, a loose bullet and the powder all "mushed" into the chamber area.
I caused this separation jam to occur by using a type of ammo that did not have a crimp. I can tell you there's no "immediate action" for this situation, you are out of action. I had to drop the magazine, rack the slide to eject the case and drop out the bullet then field strip and blow out the powder from all rails and cam surfaces before the slide could cycle. There's a list of compatible ammo on the Boberg website.
As an experiment, I ran some of the offending ammo through my Lee Factory Crimp die giving it a moderate crimp. Then I took a round, marked it's base with a sharpie and cycled it through the pistol as the # 2 round in the magazine for 7 shots. The round did not pull apart and it cycled every time.
I plan to "safety crimp" any ammo I intend to carry in this pistol, just in case.
I found the trigger to be a bit wide for my tastes and the flats on it's sides to be slightly uncomfortable as I prefer a slim radiused and polished trigger for DA work. A few minutes with a Dremel tool and some emery cloth solved this problem as you can see from the pictures.
Conclusion. My urban carry pistol of choice remains my Kimber Ultra Elite in .45 ACP. However when clothing dictates something smaller and lighter the Boberg has replaced my Colt Cobra. The Boberg is smaller, more powerful, more accurate, holds 2 more rounds and is more controllable.
I found the XR9-S to be a high quality, accurate, very controllable, reliable, 8 rounds of +P 9mm in a palm sized package. Ammo must be crimped properly or it can FTF and put the pistol temporarily out of action.