As far as the LiPo lifetime is concerned, they are getting better but I have not seen any really good studies about expected lifetimes or number of cycles. The 500 number has come up but I really think that this is pretty optimistic in a high drain application but even at 200 cycles, the cost per flight is less than glow (batteries vs fuel). If battery shelf-life is an issue, you might not finish the cells before they "expire" (refrigerated storage might help).

One nice thing about the batteries is that there is no need to reserve them for one plane. They are easily interchanged among multiple models - they come out for charging anyway.

As far as burning a gallon a month is concerned, I probably average more than that during the summer and a lot less in the winter - 12 gallons is a pretty average year on 40-60 size two stroke engines.

I am a proponent of e-flight and I think it represents the future of this hobby but I will likely wait a bit longer. Prices are coming down and quality and selection are going up. Although the technology may never "mature", I think choices will be a lot better in the next couple of years.

Ross