I did a flaps 15 landing in a 737-700 as dictated by QRH due to electric trim fail. Landed great and still made the mid field turn off.

Otherwise usually use 30, occasionally 40, but the 800 and 900's seen to get pretty roll-sensitive when doing that.

Tail is not a big deal if flown on speed. Guys get in trouble when they pull the power and float halfway down the runway below Ref.