Although a custom map is best for torque (power is debatable)... an off the shelf map still serves a purpose for those that are a million miles away from R-tech... coupled with the ease of dialing back to standard using the handheld if you have ANY problems.
Remember it's how it drives, not peak figures
If torque is better, surely power would be slightly better also as is the boost giving you the torque , the same thing that gives you power.
A custom map is about
drivability , tailoring the map to how you drive and the exact spec of your car. Generic maps are built around a "one size fits all" which is designed to work with all types of hardware so will always be a compromise.
The way I see it, with pricing differences between some of the maps available, you could travel from Scotland to r-tech, have your car mapped and come back several times before you've matched the cost of a big brand map. . .
Its down to personal preference at the end of the day, I've learnt a lot in the last 2yrs of being on the forum & speaking to tuners and for me it's a no brainier to get top quality service, a quality map for a great price