Thank you for your responses.

I downloaded the Owners Manual that covers all the Mustang amps, and as you all have suggested, the headphone jack as an output for recording purposes, is suggested in the owners manual also.

I haven't had a chance to try the Mustang I or II, I did try the Mustang III (with one 12" speaker), and even though it's a mono amp I noticed thru the headphones the amp plays some of the effects in stereo.
Still need to try the other Mustangs before I decided.

Thanks again for your responses

Bill