I can confirm that. I have tried XDA-Devs Vanilla, Dynamics 2.0 and mi7ROM WP 7.8 Nokia Edition
As far as battery life is concerned, I think the best ROM is xuantunt's ROM 8858.136 RMT V6.1 Full Unlock V4 V-PLUS. It is the only one I have found to feature Vibrate-on-answer as well. But there are some elements altered that I don't like (info in About, some chinese context).
I've used a lot (more than 1 charge-recharge cycle) a. ''xda-devs Within Vanila 1.0'' and b. ''Dynamics v2.0''.
I can confirm that. I have tried XDA-Devs Vanilla, Dynamics 2.0 and mi7ROM WP 7.8 Nokia Edition