I recently bought a Nighthawk GRP Commander, and it's a really nice pistol. I also have a Colt Combat Commander. They are both 45s so one can back up the other.
I took the Nighthawk to the range for the first time today. To my surprise, the slide was locking back prematurely with rounds still in the magazine about once per mag. I broke the gun down and examined the slide release. Sure enough, there was telltale coloration on the nose of the slide release where it interacts with the magazine follower. I used my trusty file and stone to remove a slight bit of material off that part of the slide release. Voila, problem gone.
The Nighthawk is a very nicely built and finished pistol, as you would expect. It is more refined and has a nicer trigger than my the Colt, which is a production line pistol -- typical Colt Series 80. Nothing wrong with it, but nothing too special. But the Colt has been shot a lot and has never malfunctioned once.
Now there are a couple ways I could look at this situation. I could be upset that a $3000+ pistol had a flaw that caused it to malfunction. Granted, it was an easy thing to fix and only took me a minute -- but still, one could take the position that it shouldn't have left the factory with such a flaw. Or, I could take it in stride as a dedicated 1911 user realizing these things happen -- some of the parts require hand fitting and this one got passed them. Assuming the Nighthawk performs reliably from here on I am more inclined to take the second position.
Anyway, it was a fun day of shooting and fiddling with a new gun and I was able to diagnose and fix the one problem I had. If it had been a feeding problem or something with the extractor it could have been much more frustrating.
Oh, and the Colt? Next time it goes to the range I expect it to continue its consistent dependability along with its so-so Series 80 trigger. I wish all Series 80 guns had as nice a trigger as the one on my Special Combat Government -- but then it was tuned by the CCS.