Finally! Since we got our '04 I have hated the storage situation in the basement. You know - what you want is some where toward the middle of the storage under every thing else. I had seen the slide out trays in my in-laws coach and thought that there had to be a way for me.
The upgrade is not cheap ($500+) but I can now pull out the tray and load, unload or access anything on it.
Here are a couple of photos of my tray:
http://travel.webshots.com/album/582959113yYNjfp
Here is where to get more info:
http://www.tvformyrv.com/page/452177598
My basement is not a flat bottom as it is framed up and over the black tank. But the tray can be installed!
I lost 3" in useable height and some on the sides where the slides are. I could have gone with a wider tray but actually what I got works well as I have sufficient space for my folding ladder and a couple of other long items.
And it appears that I can slide my 50A cord under the tray when traveling! That thing is bulky so flat storage is looking nice.