I've the three gun set of BP Kimbers, 3" (Ultra Ten II) 4" (Pro Ten II) and 5" (Ten II). Only the full size gun had any issues out of the box -- breech face was a little rough leading to occasional feed failures -- been fine since I polished it.
All have the "new" external extractors and none has had any extraction or ejection issues. Main problem is the Pro and Ultra mags needed stronger springs after only a few hundred rounds. Since the Pro and Full sized take the same mags it was intresting that the mags worked in the Full sized but were prone to "ride over feed" failures in the Pro.
Double stack 1911s are a big part of my collection, but I'd not highly recommend any of them for self-defense because of magazine issues -- spring life is rather short and the mags are sensitive to fouling and dirt. The "nose up jam" of the ride over feed is unmistakable. When you get one, clean the mag and if that doesn't fix it you'll need a stronger spring. Smaller guns make the problem worse.
The Kimber BP mags are Mec-Gar Para mags with differnent mag catch location (the Ultra mag is also shorter and has a very different base plate) Having had spare Woff "extra power" springs on hand from going thru the same issues with my Para mags, I discovered that the "custom fit" Para springs (#76364) work great in the BP mags if I cut the top turn where it spirals in to clip onto the Para follower. On the Ultra mags also need to clip a bit from the bottom to be able to load ten rounds or you can clip the top turn off a P14 mag spring instead of the custom fit one.
The most amazing thing about the BP guns is the grip's maximum thickness is the same as many standard 1911 grips it just is more "square" and doesn't taper as much toward the front and back.
--wally.
