The TK 12 is as tactical (momentary on or click on, twist = high, untwist = lower) as the TK11, but you can program which group of settings you want to use. It has it's advantages, but since I never carry only one light I keep a TK11 or TK20 handy for pure power only.
If you think you won't be using lower settings the TK11 is the one.