I had my bolt & action melonited and it made an already slick action even better. I didn't do the barrel since there were about a hundred rounds down it, and had heard that while a few down the pipe is ok & good (due to smoothing out the bore), anything more than a few can present some issues. Doesn't sound like you were thinking about doing the barrel anyways though, so you should be good to go. As far as premature wear, everything I have heard, is that meloniting helps with wear.
I will say, that if you are going to do any polishing of the bolt & action, make sure you do it before you get it melonited. As the melonitng hardens the steel its a little easier to do any polishing first, plus you wont be wearing thru that nice black finish of the meloniting. I polished/honed a few areas in the action & bolt and man, especially with it being melonited, it is increadibly smooth. Take a look at the DIY lightening up bolt lift thread that Cptn Kirk did if your interested.
good luck!