Sorry, but I disagree.
A shaper gives a far better cut quality than a router, and it's due to the larger diameter, not the number of cuts/minute.
Cuts per minute is meaningless without knowing how fast the wood is being fed into the cutter. Cuts per inch would provide more info. Due to it's larger diameter, a shaper is typically slicing through the wood at the same speeds a router is.
A 1/2" router bits cutting edge is moving about 29mph at 20,000rpm.
A 3" shaper cutter is moving at 70+mph at only 8,000 rpm. SO it's cutting nearly 3x faster at less than half the rpm.
Shaper cutters are more expensive than router bits because they are often 3-5 inches in diameter, rather than 1/2" to 2", and can have 3-5x more carbide in them.