Never really tried that make. Don't see any reason for them to be rubbish though. The only problem I have with unknown names is that sometimes they are made with lower grade metals which means that they corrode quicker.
You can buy kits that allow you to fit 266mm or 280mm discs to the rear. This wil give extra braking force and I have the 280mm ones fitted to mine, but you need the APs up front otherwise you will get a scary brake imballance.