We've been very happy with our I-Tech 6000/8000 and found them to be no more problematic than our MacroTechs. Our old iron Crest 8001s, however, have been the most reliable amps we've owned. To say we have dozens of each would be accurate.
You can't really compare the I-Tech to the XLS; they are leagues apart. If you're looking at IT5K-HD (or original IT), you should be looking right past the XLS Drive Core. Also, I'm not a big fan of bridge-mode operation. Get amps big enough to power your rig w/o bridging. Power is cheaper than it's ever been.
Also DSP is relatively cheap now, if you went with plain amps, but for the price of re-certified I-Techs you get a very good amp with very good DSP. If you go with Crowns, download and install Harman System Architect. It has capabilities you'll never need/use, but it's masterful at setting up, monitoring and controlling your Crown amps and other Harman group products.
Have fun, good luck.
Tim Mc