The biggest rule when using Ableton in your digital set up is the "garbage in-garbage out" rule. Every single piece of music, be it a clip, loop, or a nine-minute-long audio track, should all be lined up to the all powerful time grid. Now, this time grid seems to be the same no matter which program you use. I take all of our music and run it through Acid Music Studio first. It is easy to run and only costs $70.00 (35 euros or pounds or guineas or whatever you guys are using these days across the pond). You can literally "stretch to fit" most music. The problems start, however, when you seek to insert a piece of music where the DJ or artist has re-started their music after a breakdown or there is a slight tempo change for whatever reason in the original track. This is rectified ONLY by thoroughly watching every single beat whizz by while zoomed in at the right increment on screen and running a set, looped beat above it so you can line it up visually. It sounds harder than it is, but it does have to be done. Acid music studio does have a Beatmapper function, but as with all computers and software, it tends to be not so intelligent and needs some nudging from you once in a while. I cannot stress this enough, because the goal with using Ableton is to not have to concern yourself with synchronization while mixing/performing. Once you have your music lined up, however, you will never need headphones. We run up to eight stereo tracks at a time - Not always as it can get way too busy sounding. Minimal tracks are best used on top of entire songs, like beats or shakers, tambourines, etc... Ableton, to its credit, does play pre-made complete loops well. You just have to make sure they are all lined up to the time grid or you will be pulling your hair out wondering why this thing doesn't work right.
Kipp