Hi Jeff:
My first "real" metal detector was the Elite 2200, so I "cut my teeth" on its methodology. It has a very large LCD display and all the controls can be accessed by the thumb on the hand swinging the unit. It is very light weight and I experience no fatigue with it.
I got the Pioneer 505 about a month ago, used. It is a fine machine no doubt, however is is older technology than the Elite 2200. It is heavier and the display is harder for a fellow with middle-aged eyes to see. The 505 also has mechanical potentiometers to change the sensitivity and level of discrimination. The Elite is all solid state, with fewer openings for dust and rain to infiltrate etc. The 505 has fewer IDs and fewer tones also.
The 505 does have the no-motion, all-metal feature which, for relic hunting, is better than what the Elite 2200 offers. However when I go coin shooting and jewelry hunting, I pick up the Elite 2200.
The Elite 2200 is the same as the Discovery 2200 sold by Radio Shack.
Mark
Elite 2200
Pioneer 505
WA St.