Can't speak to the Mk7, but I had IE on my MK6 R, and I had zero issues with it. I would have had no problems going back to IE for my MK7, but it already had a stage 1 EQT with AP when I bought it. IE's facility is nice, customer service was responsive, and they made some adjustments based on what I was asking for, and still kept it as a OTS tune.
Really I'd say it's about the relationship and what you get out of the vendor that's part of the package. Email both a question, see who's the most responsive. Of course before you send them money they can always act differently than when they have your cash. But seeing people say it's been weeks since they get there tune, that's pretty lame.