So after way too many months without getting my (new in March 17) 510, I finally got to use it! What a cool rig! I really enjoy it. I'm really hoping work tapers off soon so I can use it more often. I'm even considering taking it on the road with me as I currently travel throughout the US on work assignments. Anyway, the one thing that I'm looking for thoughts and/or suggestions on is the mattress. Have any of you supplemented the mattress any for a little more comfort? It's by no means terrible, but it could be a little less hard. Or, will it soften somewhat with time? I was considering adding foam underneath for a little more give. I'd appreciate any feedback or suggestions. Thanks.