Mattresses - your advice needed please

[monkeygirl]

I'm in the process of buying a new cot and am humming and hahing over which sort of mattress to get. Do you think foam ones are comfy/supportive enough for babies, even when they reach about 18 months/2 years or is it a false economy and worth splashing out on the spring ones (I did buy one with springs for my dd's cotbed but that's because I though it would need to survive several years and probably lots of bouncing on!)

Thanks all.

I bought a spring one with unzippable top protector from Mothercare (it was in the range of £100). It was well worth it. It is on the second child and despite the protector part being washed many many times, it still looks (and smells) like new. I highly recommend it.

I initially bought a foam one thinking it would be good enough for such a tiny body,and it was half the price.
I regreted it and recently bought my ds(18m) a new sprung one as the foam one was not supportive enough(not that he told me this).I didn't like the fact that hid body left great undulating dents .
I'd get a sprung one if I were you

Our babies were in their cots for such a short time (came into our bed) and we chose foam, but the zip-off bit was soooooo good, especially for dd2 who never stopped possetting (well, she did eventually).

Thanks folks - so far it looks like it's worth splashing out on a spring mattress with a removable cover then. I'll just have to save money somewhere else...

We have the Mothercare one with the zip off cover but it is foam, it was a present, I would have chosen the sprung one, but it has actually been very good, it seems to be a firm foam and I have never noticed any indentations where DS2 has been sleeping (it is now on it's second child).

When will you need it by? Our dd will be done with her mattress in a few months (the cot isn't ours).

SofiaAmes - that's really kind but I'll need it early June (or even earlier to ease my worry about an early baby).

Demented - I will go and have a good feel of the mattresses in Mothercare I think, but I am worried that I'm 'cooking' a big 'un in my bump - I was told at a scan he already had a fat tummy!