''Is it purely just the build quality and accuracy that makes people choose an HW?''
Most probably. Lets face it, it can't be for its looks.
I chose the BSA R10 over the Hw100 because its such a beautiful rifle. BIG mistake. It was a pile of crap. Should have bought the Hw.
There's a lot to be said for them Hw100's. They might not be the prettiest gun out there but...