I have just a single experience with Eagle. Bought a pair of their Heritage grips for a 629 and wasn't real happy with the fit - there was a small, but noticeable gap between the top of the RH grip and the frame. Called Eagle and was told that there's a lot of variation in the dimensions of S&W frames (funny - never had a fit problem with other manufacturer's grips) and that I could send them the gun at my expense and they'd custom fit the grips, which I wasn't about to do. I liked the grips otherwise and you really had to look to see the gap, so I ended up keeping them as is, but haven't gone back to Eagle because of that.
FWIW, I recently put a pair of Altamont conversion grips on an old 586 I bought that had been converted to a round butt and they fit so well you would think they'd been molded to the gun.