I've used the miracle-gro for pots and containers this year (in my pots, containers and hanging baskets) with no major issues - the baskets are prone to dry out, but they are on my front porch and get the sun all day.
I'd avoid the john innes (big lumps of wood and what looks like straw in it), and I've heard REALLY bad things about the B&Q verve stuff (if you wade through the thread, not many folk have had luck with it).
Am going to try out Aldi's own compost, I've bought very cheap plants and other gardening things from there and found them brillant value and generally very healthy (as long as you get there early for the plants). I'd like to make my own compost, but space is really an issue until I get moved and have room for a couple of bins. I will post on the compost thread when I know what it's like.