If space isn't an issue, then you can pretty much design what you want. I would love to have a bigger cutting/ironing surface.
What I do have is plenty big enough to put my ironing surface on and press my material. I can remove the ironing surface and use my rotary mat. The best things are that I can easily walk around all 4 sides so I don't need to reposition my fabric/blocks for cutting and it has locking wheels so that I can easily move into a corner of my studio when not in use [not that I do that except for when i have friends over.]
To me the ability to cut from all 4 sides without stretching is the best feature, along with its dual purpose.