DH & I desperately need a new mattress after 15 years (and two of our 4 DC's!) on our current one. We are completely different sleepers & weights and I've read that a good waterbed mattress works wonders for bad backs. BUT . . . . just can't get over the 'what if it springs a leak, or 'pops' like a balloon' thing in my head. Does anyone have any experience of one? Would you recommend it?