Alltoomuch - I've been going to the Galleria off and on for about 15 years, and I get the impression they have fairly recently had a new manager, as it is definitely better than it used to be, when the Next shop was pretty much the highlight
. There is Jaeger, Austin Reed, Ghost, Clarks, M&S, Calvin Klein underwear, The Body Shop, Gap, French Connection, TK Maxx, Le Creuset, some kitchen shops etc. Plus there are a few coffee shops and restaurants (Pizza Express, Nando's and similar) and a cinema. I pop in every now and then, very often leaving empty handed, but occasionally get a brilliant bargain, usually from Jaeger, Ghost or TK Maxx.
I would say it's worth going if it's not too much of a trek, but I wouldn't go too far out of my way. As with all outlet malls, the quality of the stock is completely unpredictable, so is completely hit and miss.