x61s Wireless Card and Antenna

[denten]

While customizing X61s, I am presented with the choice of:

• Intel PRO/Wireless 3945ABG or
  
  Intel Wireless WiFi Link 4965AGN

Do these differ in terms of battery consumption? Is there a point of paying extra 30-40$ for preemptive n-standard compliance?

A related question: what is the difference between

• UltraLight XGA TFT, 2x2 UltraConnect II antenna and
  
  UltraLight XGA TFT, 2x3 UltraConnect II antenna?

The second supports 802.11n, I understand, but again: weight difference? Battery performance?

I would greatly appreciate your input and your recommendations.

[opto104]

Intel Wireless WiFi Link 4965AGN is way better in terms of both signal strength and battery consumption.
UltraLight XGA TFT, 2x3 UltraConnect II antenna does not consume extra power and adds little weight.