Thanks for the replies. I've found it easier to actuate the magazine release on the right side of the frame with the middle finger of my right hand without altering my grip too much. That is, on the side of the frame opposite the one where my right thumb rests against the frame - on most pistols with a magazine release near the trigger guard, I'd use my right thumb to depress the button. The magazine drops free when I use my middle finger but using my thumb, the button is more difficult to press and the magazine tends not to fall out. Giving it the finger, I know, very funny.
I'd read about the fix with the full size pistol magazine release and am happy to hear that works well and may do that after recall service.
There are two of those lock-up problem videos and I've been able to reproduce neither problem the pistol I've got. FN America hasn't sent me a prepaid mailing label yet although I've run my pistol's serial number through their web app and have opened a customer service case. Maybe will hear from them today. I plan to order a Theis holster with FN service turnaround time accounting for the wait on the holster.
I compared the FNS 9-c to my full-size P99 and found the widths similar, height and length shorter. The FN product is not as visually appealing as the Walther and does not have the same ergonomics. That said, I have been able to develop a grip with the FN using both flush and finger-extension magazines that I think will work fine when I finally get a chance to fire it.
Out of an abundance of curiosity, I compared my FNS 9-c with my ersatz Nanking FN Browning M1900, also a striker fired pistol designed for concealment, and found their heights and lengths roughly the same, although widths very different as the Chinese Browning is a single stack .32 caliber firearm. I'll try to snap some pictures this week and post them. Both pistols do have a similarly pronounced beavertail.
How do you carry your 9-c pistols? I'm thinking IWB at about four o'clock in a single clip holster. The two-clip Alien-Gear style hybrid holsters tend to pull my trousers down uncomfortably around my right buttock. I just don't like that.