Having had a Crimson Trace, training with it, shooting it to the point of burning out the first edition LED and having to have it replaced, I can say they have their place, especially in very dark conditions.
Having said that, if you touch that pressure pad, even by mistake, it is going to light you up like a Christmas tree and you need to be conscious of that the minute you flick on the switch on the Crimson unit.
Personally, I haven't used this set up in 10 years. I don't like them as I feel they are a distraction for me personally.
If you like them, good on you! Let us know how you do with it.