[lincpimp]

If you plan to gear for around 40, and are not trying to build the worlds heaviest crt, the 25c 5s pack will be fine. If you were going with 4s, the 30c would be a must. I really like 5s, as it takes a load much better than 4s and the addl weight is not really noticeable. 15 bucks is about the same as the faster shipping costs, which I do recommend. If it will not break your bank acct, and the 30c batt will fit, why not buy it. It will provide better performance, and will handle higher gearing if you want. These packs have not been tested throughly, but for the price you can hardly go wrong...