My Mini Summit's servo gears are stripped and I believe it's time to do some upgrading. I hear that ******* 390 and Hitec HS-85mg are popular replacements. I believe both are metal gears from what I have read. Are these the best options for replacements? Are they as fast as the stock servo? It sure seems like the stock servo is weak for throwing those Canyon AT's around. (especially when running in water and adding the extra weight) So which one of the two is better and are there any other options that I should consider.