I've had Pod2, XT and XT Pro.
The amp models in particular are night and day with the Helix. But as per any sound you may still prefer your version. It's easy to get hung up about the accuracy of amp models rather than whether the sound is good. But the IR capabilities, multiple routing for even 4 parallel paths, Cab sims on the feed to the PA and no cabs on a feed to a power amp / real cab and USB to a DAW... all at the same time is amazing.