Mechanically they are the same rifle - same powerplant, same trigger. The rear sight is different - frankly, the one on the cheaper 220 (which is shares with the Shadow) is better in several respects! On the other hand the 440 has a raised scope rail as opposed to a milled receiver, which can be an advantage.
The 22 stock is lighter and shorter than the 440, it brings the trigger closer to the shoulder. For younger shooters or those with short arms it fits well, but others might find it a bit awkward. The 220 stock is also very plain, the 440 looks much nicer. The stocks do interchange between the Shadow, the 220 and the 440 - but the clearance cut-out in the stock for the rear sight might be different between the 440 and the other two since the 440's sight is different. I believe it will work, but I'm not positive.
I believe that natchezss.com still has the 440 on clearance for $100. Right now, that's about the best deal you can get on a breakbarrel.
In either case, figure on about 900fps with Crosman Premier 7.9gr pellets with good accuracy. The triggers tend to be rough at the beginning, but there are fixes for that (CDT's trigger and the Rich in Mich insert)... and if you leave it alone, it does eventually wear in nicely. They also tend to be buzzy and twangy while firing, but again there are ways of addressing that.
Accuracy should be very decent as well - plugging a soda can at 60 yards should pose no problem.