Yes every baby is different so its kind of a trial & error with each baby...

DD had a plastic seat thing that laid down for infants & sat up as they got bigger & had a play bar accross the front of it. We ended up getting rid of that once she was sitting up & got a swivel seat... fantastic!! She loved it.

At the moment for DS we have the wire bar one with the terry towelling square. Its a real back saver for me. I use it in the big bath & it means I dont have to be "holding" him the whole time. I can kneel on the floor at the side of the bath & admire my little boy enjoying his bath, sometimes with his big sister in there with him. He never has long baths yet so we dont have the problem of getting cold.

I sold DD's swivel seat when I moved to Townsville in 2006 (I tried to get rid of all her baby items... she had just turned 1) so I will be buying a new one for DS soon for when he starts sitting up by himself.