In my perfect world, I prefer using a combination of in-ear monitors and wedges. Sometimes I find in-ears to sound a bit weak and lacking in the low-end department. They rarely feel powerful, or rocking, enough. You have to really crank the volume up, which gets to be detrimental to the health of your eardrums. Therefore, it’s great to have an 18” inch sub behind me, and/or a couple of wedges that I can isolate musical elements such as the bass guitar, the kick/snare/toms, and so on.
For elements that require more time-accuracy, I’ll put them through the in-ear’s, such as loops, percussion parts, click tracks. That allows me to use the wedges and subs for vibe and energy. Having big wallops of air pushed at you is better than having little percussive nails shot into your ear canals! In the end, this helps me keep my overall stage volume lower, which in turn helps keep me from going deaf.