The Catalina 27 is a great boat. We've had a C22, C25 and now our C34, kinda "skipping" the C27 & C30 sizes!

But they are all similar in build and good quality.
The older C27s had a chainplate issue.
Catalina Direct: has replacement chainplates, which replace the U bolts with bar stock
backing plates. This is VERY important for rig integrity.
Otherwise, no different than any other boat:
Boat Inspection Trip Tips - SailboatOwners.com
If it's an inboard, beware of limited access to the stuffing box and the rw cooled engines usually employed. If it's a freshwater cooled
engine (i.e., HX), then check on the
alternator bracket upgrade. If it is an M25
engine, our C34 website has a ton of information about them.
Capabilities? You don't say where you're planning to go, so how can we answer that part? Let us know more and we can help.
Good luck.