I have the March alt bracket too, I paid closer to $100 from Summit for it. I haven't noticed any premature wear on the serpentine at all, but you have to have it adjusted to the exact correct tension to be safe for the belt as well as the accessories. If you burn up an alternator and don't tell March it was set with a precision belt tension checker, they don't want to hear about it- and that tension gauge isn't a cheap tool considering what it is. Just using the old thumb and forefinger "belt twist" check isn't accurate enough. The stock tensioner pulley actually does have an important job to do, and the March bracket doesn't do it anywhere near as well. I don't like it, but it was cheaper than the stock alternator bracket when mine broke- and it is purdy...