The XTL.... so many possibilities to do.
I send the POD output to the effects return and set the output to "combo pwramp" to get the best tone. then spend time rolling your own. tweak lang ng tweak ika nga.. If your amplifier has no effects loop you have it setup with "Dest" being a "Combo Front" and plugged into the front of the amp, set the amplifier's EQ as "flat" as possible by turning the treble and bass controls to zero and maxing out the mid control to avoid stacking two preamps. as a "stomp box" of sorts for fx and cleans ubra din if you turn off the amp modeling. as there are a million and one things to do with the XTL, to read the manual and explore the many amp,cab,fx and mic placement options.
Hope this helps to get you started.. I am still pretty new to the behemoth known as the POD XT Live.. mismo!