I have made Maloof inspired furniture including the Rocker. The RAS wasn't an option when I built the first. I use a hand held grinder with a King Aurthur tungston carbide bit. This approach works well but makes for a terrible mess. I've have used the RAS and the dust collection should certainly be a consideration. I don't use the grinder for anything but the seats and it goes very fast. The vast majority of time is spent in finer shaping and in sanding. Having said that the RAS is much easier to control and I might be tempted to use it on the arms and backs as well. I'd think the 24 grit would work great as you are getting material off fast.
The RO90 is a fantastic stander for both fast removal (not for the seat however) and finer shaping. It isn't a replacement for the RAS but worth considering. I'd buy the RO90 before the RAS. However, I wish the RAS had been an option when I started. I might have to replace the grinder yet some day.