I've used them on 5 of my cars, and always had a great experience. They used to get a model in, do all the development on their rolling road then offer the map out, tried and tested. I've had a few cars custom mapped before on a rolling road and never been happy with the end result (apart from my map from EFI which was good!) - So superchips were my go to and who i always recommended.
Then as most will recall, they went bust a wee while back and got bought out by "Remap Kings" who were a mobile remapping company doing flash maps from the back of vans. My understanding is Remap Kings bought out superchips and started to re brand their current fleet and now use the superchips name.
I got a bluefin for my Mrs mk4 Clio, wouldn't connect to the car, they then sent the mobile guy out, turned up in a remap kings van, couldn't remap it, he had just started that month so hadn't done one before.
I then ordered one for my Kangoo once it was out of warranty, arrived, wouldn't connect, they sent the same guy out, now with a Superchips van, got the map installed, drove perfectly for 5 miles then started repeatedly spitting the dummy and going into limp mode. They came back out, flashed it back to standard, we took it a run, drove perfectly, flashed the same remap file back on, started faulting again.
They were certain it was a fault with the van (not impossible but ive owned it since new, its now 3 years old with 20k miles on the clock, drove flawless from the day i got it and drove flawless back on the standard map - so highly unlikely)
I really liked the way it drove when it wasn't faulting so tried really hard to work with them to get to the bottom of it, doing data logging etc for them but they weren't interested and just kept suggesting the van was faulty and they would refund me if I wasn't happy, so that was that!
after years of good experiences and recommending them, I wouldn't touch them now, they are no different from any other company flash mapping some random file onto your ECU