I play in a rock oriented top 40 cover band and this Flextone III has been a great amp for me. I bought a separate 1x12 extension cabinet so I could take advantage of the stereo ping-pong delay, but as good as the built in effects are, I found them limited and they do have some drawbacks. This lead me to invest in a Line 6 M13 effects board which I've owned for about 6 months and it's just last night that I had an epiphany and realized what this particular combination of gear is capable of. All I can tell you is that the results are UNBELIEVABLE. If you still have your Flextone and you have an extension cabinet as well - you MUST get your hands on an M13 and set it up with the stereo effect loop. My rig is set up now so the M13 goes into my amp through the stereo effects loop and delivers the richest and most incredible stereo effects I've ever heard. I have an FBV controller that sits beside the M13 that I use it to switch between clean, boost, crunch & distortion channels. (I don't use the flextone effects at all any more). Bottom line, there's nothing I can write here that could possibly describe how amazing this rig sounds. LINE 6, you guys are awesome!!