Wings - Speed and ecspecially torque are critical to me in my Fun Flys, because I prefer it, but this is my personal preference. I run the NiMH, as you claim that you do, and I see, comparing them to comparable NiCad batt. packs, at least two extra flights between charges, and significantly less need to cycle NiMH (which is an advantage of the NiMH). Regarding a regulator dumping - Sorry I don't agree. I've never seen a regulator used for RC application shut-off batt. voltage. Besides, a RC regulator is designed to prevent any more than 6V to pass through it, not to include a shut-off a be predefined low voltage.
BTW - its Kevin, not Keven

Outsider - Pls ask Airtronics if they will warranty their receivers with a supply votage above 6V? And at what voltage point will they void that warranty? All receivers are designed today to handle 6V. The problem is that a 5 cell pack will produce a significantly higher voltage over 6V, thence the need for the regulator.

Guys - needless to say, it is your choice. The original question was whether it was worth replacing a bad 6V regulator or not. Well, IMHO, I say yes, its worth the insurance policy, and if I am running standard servos in one of my Fun-Flys, I run a 6V pack with a regulator because I feel that I need the extra torque, and I like the quicker response rate.
That is my 2 cents worth!
Kevin