Craig,
I have a SureFire G2z with M61HCRI-L, a SF 6P with Malkoff M61W, and an EagleTac P20C2 MKII Neutral. All are 2xCR123 warm or neutrals. I love them all, but for different reasons:
The M61HCRI-L is a nice warm, almost incandescent beam. It's very smooth, broad, and even. Great for lighting up things that aren't too far away.
The M61W is a little whiter to me than I expected - it's cooler than the other two. It puts out a great wall of light, but still lights the tops of (really tall!) redwood trees at the far side of my local park.
The P20C2 has an XR-E, rather than the XP-G, and it shows. The color is perfect - I use it in the morning in my sock drawer to differentiate the navy from the black. Also, when walking the dog, it doesn't wash out the trees and fences. It has a tighter spot than the Malkoffs, and throws as far as my (much larger, cool white) TD-15x. It lights up stop signs and reflectors 4 blocks away. Unlike the Malkoffs, it's a multi-mode light. For socks and night navigating, the 4 lumen low is fantastic. Walking the dog, I usually keep it on the 60L medium. The light really comes into it's own on high - the spot goes forever, and the spill fills in nicely. The light is also the tiniest bit shorter than either of the SF's, and quite a bit lighter. Finally, the Malkoff modules tend to run $70, and you'd be hard-pressed to get an actual SF host for under $30 - my 6P was $60, while the G2z was on sale for about $45. The P20C2 was about $75 including shipping. I find it a tiny bit large for EDC, but it's one of the smallest 2xCR123 lights around, and I carried it for 2 months while my single AA EDC was down for service, with no ill effects. I highly recommend it.
I'd love to try a neutral T20C2. I'll probably use GG or PTS when I buy my next neutral EagleTac.
Good luck.
- Tom