For the longest time Shapeokos came with the Dewalt 611 by default. That has a speed range that is higher at the lower and lower at the higher end (16,000 - 27,000 rpm) than either the Makita or the Shapeoko. Consequently I don’t think the difference between 10,000 and 12,000 is that a big deal.
While it would be nice to have brushless motors, the spindle clamp only accommodates the two trim routers you’re considering. On the plus side, if I remember correctly, the Shapeoko spindle comes with spare brushes.
Since you’re thinking about how to get started you might also consider a water cooled spindle much like Mark Stook has installed. I was tempted and I remain tempted but for now I am happy with my Shapeoko spindle. We’ll see if that changes in coming months.
Congratulations on getting yourself a Shapeoko!