The differences between the AVR-225 and 125 is 10w, an On screen display, "EZ Set" speaker calibration, and one extra AV input. I have the 225 and I don't use the EZ set feature (Avia and RS SPL meter for that) and the on screen display is nothing special. There are no Pre-Outs for a seperate amp but there are inputs for either DVD-A or SACD. I got the 225 for the extra AV input and the 10w. I'm not sure if the 125 has the 6ch analog input (DVD-A/SACD).