+1 on Carrot's thought.
If you are just getting your feet wet with HDS lights, I don't think you'll go wrong with the 120. Same features as the higher output lights, at a bargain price. If you like it, which I suspect you will, you can always get another. :devil:
If you are set on more lumens or have need for max throw, the 170 is a better choice, but for EDC, I don't think it's crucial. I mostly use my 170 only because it's wrapped in Ti.
High CRI lights are available on the MP if you watch for them if the accurate rendition is important. I like mine, but personally I don't mind the cooler temps so I use my 140 a lot too.
If you must have the latest, and don't mind a possible bug, the Rotary is the most ingenious UI, and ensures you are cutting edge. It shares the XP-G with the newer clicky 200 and they have a softer floodier beam than the 170.
Some things to think about.