I agree with the posters that recommended using Aux to SIF - preferably the highest level you can put in there.
I use cruisers most of the time and that's always the Commander level ability I put in there. The best thing about it is that you can cycle it constantly with its 15 second cooldown, so you are getting a fairly regular hull repair and resistance buff.
Considering the aux power emphasis on most science builds, and what frail armor most science ships have, I would imagine that rotating this skill consistently would increase survivability by a LOT, as it's using one of your most noteworthy strengths to provide a good patch to one of your weaknesses with little cost.
It is worth noting however that Aux to SIF is inferior in terms of burst healing, but if you're using another Team power, chances are you're not going to get much mileage out of ET anyway. ET CAN be fairly solid on cruisers if you can part with your Team powers for long enough to make it count (particularly if repairing a damaged teammate), but I wouldn't put it on a non-cruiser, as it's a waste of a BOff power that could be used for something more useful. This in itself, however, is partially mitigated by the fact that Aux 2 SIF can repair and buff teammates as well.