Pretty good light. It is one of CPF's all time favorites. It now comes with an XP-G R5 emitter. Compared to the last version it is brighter, bigger spot and brighter spill but has less throw. They have a version with a side switch on the tail cap for easy access to the strobe. It is a bit bigger than the P20 you are looking at. The P20 can be carried in a front pocket as long as you aren't wearing Chuck Norris tight jeans. The M20 is on the big side if that is your plan. Here is a picture of a P20C2 next to a EagleTAC T20C2. The EagleTac T20 is the same size as the Olight M20 so you can get a look at the size difference. This picture is from a review from Wattnot. I hope he doesn't mind. The T20 is the middle and the P20 is on the right.
I have 3 Eagletacs - a M2XC4 MKII, a P20C2 MKII and aT20C2 MKII. In addition, I have a T100C2 MK II arriving either Tomorrow or Tuesday.
I love these lights.
I ought the P20C2 Mk II first. I actually prefer it a little over the T20C2 Mk II - as is had more flood. It is my every day carry light. And, the size is nice too. I prev carried an Inova XO3 for a year - so this is much smaller for me, yet much brighter.