I'm a little late getting in on this, but I think you made the right choice! The 2 machines in question were similar, however to me, where it counts in a GT is the Transaxel! The X500 with the K72 is no doubt superior to that of the K66 found in the Husqvarna GT48XLS. You can have all the HP in the world, but if your transaxel sucks all that power isn't good for much. That doesn't mean to say the K66 sucks at all, just the K72 is in a class above no doubt! Now my machine the GTH27V48LS has the Hydro Gear G730 which is a lot closer in comparison with the K 72 so that would have been a tougher choice, especially with the money being so close. But the choice you had to me was a no brainer! Have fun with it!