I used the Rosemary and Co series 401 brushes too, really liked them until they started hooking thanks to the synthetic fibres, it's possible to reshape them by quickly dipping them in a cup of boiling water, but this got a little tedious, I switched to the series 33 kolinsky sable brushes and I love them, they're every bit as good as the W&NS7 I tried out
also the importance of brush soap cannot be overstated! I use the Masters brush cleaner and preserver, it's really good stuff
on GW brushes, I have several from the past generation (coloured caps on the handle) and I think their issue is a lack of good quality control, some of those brushes were truly awful, but I have a couple of gems that I still use, they get battered around overbrushing and applying washes and sometimes textured paint but they have soldiered on and been pretty good, and it's rare I find much to compliment about GW
also their last range of drybrushes has yet to be remotely equalled on the market, I pick them up whenever I have the chance!