I would definitely recommend the Hirst molds. We (Gaming club friends and me) ordered some together (and later some more) a little while ago. Before hand I was a bit skeptic about how this would work out, but the molds and bricks really are top quality and it's rather easy (and good fun) to build with them.
What really surprised me was the relative ease of getting good paint results. The brick have a very nice texture and they become very good looking just by dry-brushing. The basic way I use to paint the building is by spraying with black undercoat, and then two or three layers of dry brushing.
After that I give some extra attention and details to 'special area's, but about 90% of the building is finished after the dry-brushing.
My advice for starting with this would be to buy one or two molds with some good basic blocks in them. For example, for the watch tower I mainly used brick of molds #50 and #61. I borrowed some bricks from other molds like the stairs (#60) and some floor pieces and decorations (#281, #282). (Another tip: The tiles in #281 make great bases for miniatures).
Hope this advices is useful (I really really really don't own any Hirst stocks :-)
Regards and thanks for your compliments!