Yes, we have used cranksets from both manufacturers. I like the easy setup of the external bearings and through axle vs. the old Octalink/ISIS or square taper. They may not spin as freely due to tight seals, but otherwise very simple to install/uninstall.


Shimano:

Nice stiff cranks.
Decent Q-factor.
Hollowtech II BBs. Pretty standard and cheap replacements should you need them.
The r603 comes with chainrings of 52/39/30. You can change out the 130mm BCD 52 ring for something like a 53 easy enough, but pretty much stuck with the 39/30 due to the 39 being a triplizer (not easy to find these in other sizes) that holds the 30t granny.
The shaped big ring is nice and stiff, plus the clean look hides all the chainring bolts mounted from the inside.

FSA:
MegaExo BBs. Proprietary.
Other attributes depend on the specific model.
More or less standard triple ring BCD sizes (130/74mm), so easy to find rings of various sizes.
I have had a FSA alloy self extracting bolt head snap off. Best to replace these with steel bolts.

Shimano rings are known to have better shifting performance than FSA.

There is a set of Shimano Ultegra r601/r603 10spd cranks on eBay at the moment. It is a very solid set of cranks, rated one of the stiffest and not too heavy either.