Moving from Memory Foam?

Hi there,We have been fairly happy with our bed, a Sleepshaper Duo pocket spring and memory foam, which we've had for about seven years. However, a while ago I tried to take off the zipped cover to wash it, failed, but realised it had two big splits in the foam. Since then it seems to have become noticeably less comfortable, and I realise we need to think about getting a new one. Haven't been overly impressed with the memory foam - it's very comfortable, but we feel it's maybe not as well constructed as a more traditional bed and apt to lose its shape over time. Also, I find it gets too warm in the night (though my husband doesn't mind this).I've been looking at mattresses for about a week now, and frankly the more I look at, the harder it gets to decide which way to go. We did look at the Sealy Pocket Teramo, because of all the rave reviews, and I found it very comfortable to lie on - but then I remembered what you said about the pillow top mattresses, and it has made me wary of that one. My other idea is just to go for a good quality, old fashioned springs/" title="pocket spring">pocket spring mattress, and my husband says he's happy to forego the warmth of the memory foam and feels instinctively that we'll probably end up with a better mattress if we go back to basics. We are both pretty short - I'm 5'3" and he's not much taller. Both weigh a few pounds under 11 stone. He says he prefers firm to medium comfort, and wants to feel well supported - and all that sounds good to me too. We have a pine standard double bedstead with a slatted base. Can't afford much more than £600. Any advice at all would be much appreciated. Thanks!