I had the exact same thought as you when I had my manifold and head off a couple of summers ago.
I ended up taking the starter apart, confirming how amazingly good shape it was in at ~186k miles (2001 3.0i). I ended up replacing the brushes, regreasing things and putting it back in. I can't say it's any better, since it was pretty much perfect before.
The brushes (4 of them) had about 70% of their life left. Everything moved well, all contacts looked good, etc. If you find similar, you might just want to regrease and reassemble.
It was a little tough finding the brush assembly, but I did. Let me know if you want me to dig for part numbers.
Here are some pics:
