There are different grades of Mintex - standard is '1144' and a slightly better compound is '1155' - I've tried both and found them to be fine at town driving and gentle A road trundling. As soon as I gave them some grief though, I boiled the pad material (not the fluid - I actually had clouds of smoke from the wheelarches as the bonding resin melted, then boiled away)
It depends what you want your car to do - if it spends 90% of its time in town, with just the occasional countryside potter, Mintex will be just fine. However, if you tend to use the car's potential, I think you'd find them to be inadequate. If you're well-modded, I would strongly recommend you buy the best brakes you can afford, as a modded Coupe can get to silly speeds very quickly.
Ask Marco, Begbie and Mario about brake fade when I took them out for a spin in my car at the AGM...