I'm not a big believer in "refresher" scuba classes if, for no other reason, than too often they aren't "refreshing" anything of importance since:
a. They tend to be 20 item checkoffs; and
b. The most important skills (i.e., good trim and buoyancy control) weren't all that solid to begin with.
OP -- you write that you are PADI AOW and have about 60 dives but haven't been diving in 4 years. OK, over what period of time did you do those 60 dives? Were they done where you now plan to dive (in particular, if done in warm water and you are now planning cold water)? Really, how good were your skills when you were diving -- and in particular, your trim and buoyancy control?
Please, go talk to your LDS and the instructor(s) there to discuss what they think you should do, why they think so and what they plan to have you do.
IF all you've done is OW and AOW, then instead of a "refresher" -- how about a Peak Performance Buoyancy Specialty class or some such -- but make sure it includes at least one confined water session to help get you back in the swim of things.
At 4 years out of the water, I'd almost suggest you do OW again -- especially with the new PADI Open Water program with its emphasis on buoyancy control -- AND make sure the instructor does it!
Anyway, that's my two cents and worth every penny you've paid for it.