I own a PODxt...it has it's applications here and there.
I own a SansAmp...love it...use it alot.
I have found however that my POD through my second bass rig (vintage Kustom 3x15 + 200B head) sounded A-MA-ZING when I dialed in a particular cab and amp sim...I don't know why, but it just does.
curiously enough, my other rig is an Ampeg 1540HE and an SVT-3, and the cab sim I used on the POD, through the Kustom was the Ampeg 8x10. Go figure...