I use my Bayou Classic Turkey Fryer. I've done extract brews in it and I'm ready to begin AG batches (everything willing, this weekend) with it.
I can say this, versus a stainless steel pot on my kitchen stove it kicks butt. However, it's only slightly faster doing a full boil than doing a partial boil on my stove. If you're still trying to figure out if homebrewing is for you, grab a turkey fryer! You'll love it!
If you already KNOW howmebrewing is for you (I knew after batch three and 20 gallons of apfelwein I was going all the way) then spend some money in a high powered burner and a nice LARGE kettle (aluminum is fine!) because the speed and efficiency will pay for itself after a few batches.
Good luck! In the end the brewer, not the equipment, determine how good a beer is.