You should base your choices on some factors.
1. Product feedback - does it get good customer reports.
2. Do you want the tuner to be close to you? ie How far do you want to travel. Sometimes people prefer to use a tuner closer to them for piece of mind.
3. Features, does it allow switching of programs, valet modes, anti-theft etc.
4. Do you want to go further, is the map upgradeable should you start fitting extra modifications, such as full exhaust and downpipe, fuelpump, intercooler, intake etc etc
The popular choices such as Revo, APR, Custom Code, P Torque, Bluefin all have their followers, but at the end of the day they are all there or thereabouts doing a similar job. Some tuners maybe more aggressive with their maps, stronger mid-range, more top end, some may map for a smoother on road performance.
Bear in mind also that a stage 1 map on a Cupra can be limited in what it can give you. The TFSI engine essentially has a ceiling point at which the fuel delivery/fuel pressure becomes a
problem across a certain part of the middle rev range. If a map attempts to push the output past the point at which enough fuel can be delivered across that mid-range, the car will momentarily cut-out and essential be running lean which is bad long term for the engine.
On stage 1 maps tuners tend to flatten out the mid-range to prevent the fuel cut-off from happening, but they usually recover some of the lost power near the top of the rev range, so good top end power.
Hence tuners have developed modified fuel pumps such as APR's replacement fuel pump solution and there are other ad-hoc solutions which replace the internals of the stock pump. These modifications increase fuel delivery so allowing stage 2 maps to be developed increasing power output safely without fuel starvation.
Across the mid-range a fuel pump upgrade can harness upwards of 40-50hp more, which is very noticeable and a useful power to have in the area of the power band you make the most use of.
