Hi Scott,
I used to be the biggest aluminum fan, (when it came to flashlight construction), that you ever saw. I couldn't figure out why folks would want a "plastic" flashlight. I still love aluminum or metal lights but when I tried out a G2 awhile back, I was amazed out how much I liked it! As the gents above mentioned, it's tough as hell, doesn't dent and is very light. I really like this Nitrolon stuff!
As Quasar mentioned, for a minimum outlay of cash, you can do the easy Ozark Trail clickie mod that Chop came up with. Also you can order a 29.1mm UCL lens for the Pelican M6 from Chris at Flashlightlens that pops right in the G2's bezel. These two mods alone transforms the G2 into what it should have been in the first place!
It's your call though my friend to decide if you prefer aluminum over Nitrolon. The "modded" G2 is a great light and for around the same price, (WITH the mods!), as these discounted 6P's, TO ME, it's BETTER light!
Then down the line, you could even go the BIG extra mile and get some Pila 168S Li-Ion cells, a charger and a Pila 3.7V LA and it's really a winner!