It's not 'their' remap, it's from JBS Auto Designs, and it's more like £350, not £250.The car looks great, but at £20,000 there are better options.
Their remap at £250 would be worth a look though.
The Up GTi is good because it is (or was) a performance car bargain at around £13,000.
Sure it’s not perfect or a “proper” GTi, as has been discussed on here, but at the price you could forgive it.
At £20,000 the car becomes too expensive for what it is.
Tbh you'd be surprised, 140bhp and a decent map are not beyond the capability of the engine or brakes. It's not that big of a hike in power, mine mapped at over 120bhp stock so the increase was less than 20bhp. The main difference was the way it delivered that power and the relationship to the throttle pedal.The Up GTi is a balanced package as standard, and dumping a wedge of extra power through it will likely highlight the budget chassis/suspension/brakes.