Arm's Reach Co-sleeper - do I need to buy another mattress?

[LAParent]

I've read that the mattress that comes with it is too thin and hard. Should I buy another one? There is a portacrib mattress on sale at Babycenter.com, and I am tempted, but not sure I need it.

If I don't need it now, could I use the mattress later when the baby has grown out of the bassinet and we use the playyard feature for naps?

[westchicagomom]

We have the mini and the mattress is thin and hard. It now has a big indent where her butt and head were. I guess the thin and hard is for safety reasons. If you put too thick of a mattress in there then when you have the bed-side down the baby might be able to roll out.

My dd didn't seem to mind. But if you could use it later - then maybe you should get it if it will snugly.