Yuh huh - nothing like a GAU-8 spitting fire to maximise the
pucker factor! 
In a strictly anti-tank role, I'd bet on the A-10, although it's a
tough call. While the Apache's got 16 Hellfires, each warhead
carries 1/20 the charge of the Maverick, 10 of which can be fitted
on the A-10. The Apache's got longer range, but in either case, the
typical operation method for both aircraft would be to be guided in
by a spotter anyway, so that's not really an issue.
Ultimately, I think it comes down to the lower likelihood of an
A-10 being taken out with an RPG, compared to the Apache.