There is a very minor difference between the TR3AP3 and TR5AP…
1.1 ghz processor for TR5AP and 1 ghz processor for TR3AP3
I think the dvdrw in TR5AP can write to +R/+RW also
As far as TR3AP3, AP2 and AP1 are concerned, the only difference between AP3 and AP3 is the dvd writer inside AP3 compared to a cd writer in the AP2. Rest are same like wireless g, 40 gb hdd, 1 gb RAM, etc
AP2 and AP1, the difference is 1 gb RAM in AP2 compared to 512 mb RAM in AP1. Not sure, but the AP1 might also have wireless b internet.