Ok I've been sanding resin/wood boards today, and what would normally take me at least an hour on the inside curves by hand, I could do in roughly 10mins using the Mirka.
If you're doing a lot of small radius inside curves, the 3.0mm RO would be the better choice over the 5mm RO if you only got one sander. And don't fear, the grunt of the 3.0mm has to be seen to be believed, moves an astounding amount of wood!
The other thing I do to cut down the time is use over size sanding sheets/discs as shown so the edges roll up as seen below. I also use 1500g 77mm diameter discs as the final sanding, before hitting the board with Abralon pads.
I'd estimate I'm saving at least 1.5-2.5 hours per board, depending on the type of board.