I have a G20SF and a G29. I'm wearing the G29 right now in a Milt Sparks VM2, which alogn with a good gun belt, makes a phenomenal rig. It hides and wears really well, just as good as the G27 and same model holster I have.
Now I also have a G21. The SF frame is a lot more comfortable if you ask me. The regular one feels a little large, but the SF frame feels just right to me. The G29 I have is regular, but I don't complain --I've never felt the SF version though.
For carry, definitely the G29, no doubt about it. Get G20 mags as backups though, and get those pinkie extensions for your carry mags. I agree, they should be stock on this pistol.
I think the G29 is easier to shoot and handle than the G27 is, and I've heard my friend's 16yo daughter say the same. That particular day, she was shooting 200's in the G29 at the same speed as 180's in G27. It handles heavy loads very well too, and I find that the G29 is just a more accurate pistol than the G27 is.
I love mine, and I think it is one of the best compact carry pieces out there. Certainly doesn't have any competition. It is just as reliable as any other Glock too. For a carry load, I like 180gr. Gold Dots at between 1100 and 1200fps. That is the actual speed from the actual pistol, not a box number. Not bad for a compact, and they are pretty accurate loads too. XTP's are a good 10mm round and super accurate, but they also penetrate more than just about any other round --I've heard of 200gr. XTP's loaded hot plugging up and going a few FEET in gelatin. So I only use the Gold Dots to be on the safe side for carry, they are soft and are known for expansion. Don't worry about penetration with a 10mm, you don't need to at all as long as you don't use 135's (which are known for just fragmenting at 10mm speeds, but also known as good target loads).
But yeah, for carry you want the G29, not the G20. Obviously both aren't bad either. 10mm is addictive, so you'll need to load if you don't, and since you'll be doing that you'll need the Smith and Wesson 1006 so you can shoot nuclear handloads. At least it all worked out like that for me. 10mm is a great do it all round, it really is, from mild to wild, and you really can't go wrong with any of the defensive loads, even the watered down stuff (which is kind of what you want).