A little deeper... I'm gonna build something like this:
Good job on the video Ryan.
Festool actually makes two different 'plug it' cords, one is a little heavier than the other and is used with the track saw and larger power tools while the lighter duty cord is for use with things like their sanders. If you look at the 'plug it' end, you can see that the heavier cord has a 'notch' where the light duty cord has a 'protrusion'. You can use the heavier cord with every tool but you can't with the light duty version. I don't know why they just don't use the heavier cord for everything?
I would say (and remember I am a 'hater' lol) that the MFT Top is one of their best ideas. I would never buy the MFT/Card Table - but as you mentioned it is fairly easy to make your own. A lot of people start with the Paulk Workbench plans and modify them to suit your need - that is what I did
Paulk Workbench plans
http://www.paulkhomes.com/order-plans.html
Now - the fact that you are planning to build a 'base' for your mft... I can't help but think,
you could have just bought a decent table saw...
Example - if you really wanted to be 'safe' the SawStop jobsite is $1,200, and comes with a cart. If you wanted to, you could build a similar base for it, make a larger top and add some more tools.
Note - The Festool MFT with the cross member support is almost $900!
Getting back to the MFT Top - there really are some neat accessories for it. One of them is the "precision plate" that allows you to mount an Incra Fence to the top. Cut in a router lift and not only do you have the clamping and positioning capabilities of the MFT Top - but you also have a decent router table. Add a smaller 'jobsite' table saw like the sawstop one I mentioned and you have a pretty decent work area - not much bigger than the one you pictured.
Precision Plate
http://precisiondogs.us/products/precision-plate-v20
Incra Super System Fence
http://www.incra.com/router_table_fences-ls_super_sys.html
Incra Master Lift
http://www.incra.com/router_system_accessories-mast-r-lift-ii.html
Incra Dust Collection
http://www.incra.com/router_system_accessories-cleansweep.html
Here is my Paulk Style top while I was making it - I will have to see if I have any better pics. I have a Ranger Motorcycle Lift Table and it was sized to fit on the top of it. It also breaks down into two pieces for storage. Last pic isan example (not mine) of what I am talking about