I would think the rounded grip by whatever name would be more difficult to get "right" than would the traditional grip cap.
It would also depend on what you mean Andy when you say "inleting the grip cap" because by that I take it that you are talking about a skeleton grip cap and a simple way to do a first one, is to take a slice of walnut from your blank that will give a reasonable colour and grain match for the end of the grip and fit it into the grip, and then screw the cap to the bottom of the grip area. This allows as many attempts as is necessary to get it right and you will be practicing your inletting and learning a whole lot at the same time, while developing the necessary skills.

Welcome to NE and do post pictures as you progress with your stock.

Von Gruff.