Academy's Apache is marginally better. It allows you to build a MSIP AH-64A, right up through the Longbow Demonstrator (this was an 'A' model with the Longbow Radar installed), where Monogram's represents an early Apache. The fit isn't as rough as Monogram's, plus it has recessed panel lines (what few there are on an Apache). Surface detail is decent on both kits. Both kits have good cockpit, but could use some extra detailing as there were some electronic gizmos that were overlooked.
If they're roughly the same price, I'd go with the Academy kit over Revellogram's just for the fact it allows you to build a more current Alpha model Apache.
HTH,