Dell XPS 702X - RAM modules from different brands

Got my XPS 702x a couple of days back.

Spec - i7-2630QM, GTX 550, 1080p AG, 6GB (3+3), 500GB 7200rpm + Intel 6230 wireless + BT 3.0 + X-Fi

For those who want to know:
* 2 RAM slots (as expected)
* 2 HDD slots with the empty slot having the caddy as well (Thanks Dell)

Problems I am having:
1. Battery life sucks big time. I had earlier tried the NEW, Revised, second gen HP DV7TQE with a similar spec (minus the e-SATA and USB 3.0). The 6 cell battery on that HP lasted for 4+ hours easily. With similar use, the 56 wHr on this Dell XPS lasts under 3 hours. I cycled the battery completely over two consecutive full charge/full discharge cycles and it is on it's third cycle now. No change! Charger is the 130W Dell branded one.

2. The CPU-Z reported two different brand modules in the two slots. One is a Samsung (green board) and the other one is Nanya (blue board). They are both running on the exact same spec (of course). Should I be concerned about the different branded modules? Should I ask Dell to send me a Samsung pair instead and send these back?

Overall, the laptop is fast, but not blow-me-away fast!

Don't know if it's AERO and/or the McAfee that's slowing it down! I expected snappy with the snappy cut further short in some cases! Don't get me wrong....it's plenty fast but...maybe I expected way too much!

I am liking the 1080p AG screen out of the box. It should only get better once it burns in a bit and I get a chance to calibrate it.

Hopefully the experienced will chime in with their thoughts soon as I intend to call Dell tomorrow to discuss the battery situation. In hindsight, I should have gone with the 9 cell ....but regardless the laptop draws way too much OR the batteries are pathetic compared to the HP I had briefly and was returned because of BSODs, involuntary reboots and system freezes! The Dell on the other hand is extremely stable so far!