How do we use our Arms' Reach with Sub mattress?

[mrsbernstein]

Hello!

Our LO is due any day now...and the Arm's Reach is assembled and in our room.  We just put the cover on it...and I have some questions.

First, is there supposed to be extra bulk where the side is down for co-sleeping?

Second, we purchased an EcoBaby Wool mattress to replace the pad from teh ARC.  However, the mattress is not sturdy enough to just sit on the bars.  Do we have to put the mattress on top of the ARC pad?  Doesn't that defeat the purpose of WHY we spent so much on the wool mattress and organic cover?

Thank you!

Mrs B