Was there anything about the 1042 that you were unhappy with? The Aprilaire is essentially the same design/type, so you really won't see any improvement over what you have now.
Do you trust your HVAC tech? I'm quite surprised that you need to replace it. The only two things that can really go bad are the pad and the solenoid. (And both can be replaced fairly inexpensively)
The AA's are very good humidifiers, but I don't like the plastic clip that holds the water line above the pad as they tend to break.