Apologies for dragging this one out of the archives
I was thinking of using Click's Define range of gridswitches until I read this thread :_| . Has anyone been using them recently and found them tacky/ cheap looking? I asked Click about backbox depth and they said:
The Define range of products will fit onto a 25mm box if required. However, your electrician wont thank you for it when it comes to double sockets that are on a ring main! If you're looking at fitting new boxes, go for 35mm. If you already have 25mm fitted, you will get away with it but some of them will be a little difficult to fit.
...why he assumed I wasn't the one doing the job I don't know... ; \
I use click quite a lot, and generally had no problems with them. Slightly better looking than the really cheap stuff, but a bit basic as you would expect for the price. Grid switches are OK although i haven't used many of them so far.