Regarding the "studio monitors versus live rig" conversation...Generally speaking, decent studio monitors will typically give you more high end and less low end than the average monitor wedge, or FOH mains. Unless you've got a sub in your studio, most studio monitors have a 6 or 8 inch speaker for low end. That's just not going to compete with the low end of a much large speaker (12, 15, or 18 inch). Studio monitors also have a more responsive high range (again, generally speaking) than the average monitor wedge or FOH system. Additionally, you're typically going to be sitting directly in front of a studio monitor, within a few feet, and basically at ear level. Given all of that, sounds dialed in on studio monitors will often sound thin or even shrilly on a monitor wedge or FOH system. The quick and dirty fix is to EQ your studio monitors to compensate for that. If at all possible, also double check your patches on something similar to what you'll be playing through live. If you don't have that option, take a look at what the FOH person is doing EQ-wise to your guitar, and that'll at least get you pointed in the right direction as far as EQ compensation when dialing in patches on your studio monitors.