I'd give TDI-tuning a wide berth. My first foray into tuning boxes was with my MK7 GTD. One of the first companies out there with one for the GTD was TDI-tuning, so I got one.
The car ran like a bag of hammers, the frequency of my DPF regens more than doubled, my mpg dropped right off and the power delivery was brutal and crude.
I sent it back with my misgivings and they "tweaked" it. In effect they cut the power right back, making it pretty pointless.
I gave up on tuning boxes for a while until DTUK brought one out. They were local, so I paid them a visit and tried before paying - the difference was like night and day - lots more power, delivered smoothly and no negative impact on mpg - the frequency of my DPF regens halved vs stock.
Andrew at DTUK gave me the opportunity to get involved with the develooment of settings for his new "Trevor" box, and I saw just how much development goes into his products.
I know your car is a petrol, so some of the considerations won"t apply, but i'd put more stock in DTUK than TDI-tuning for the reasons above.
If you look at the TDI section around Jan 2014 you'll see my comments on the tuning box saga.