I'd like to reiterate Brice's point about describing your needs more. Posting a pic of your shop and maybe a typical setup on your job site would help tremendously.
The key issue about needs is (obviously) that needs, situations, and perceptions differ, and the the exact solution combo is unique to each user. For example, Brice's needs and mine are pretty different most of the time. But sometimes they are similar.
This weekend I'm installing the final small pieces of drywall for my master bathroom remodel. I'll be taping for the next couple of weeks. I don't know if Brice does that professionally (I believe he focuses on finish carpentry). However, in a month or so, I'll be installing a new door, trim, cabinets and wainscotting. Then, I suspect that his needs and mine will be more similar. My point is that it's important to all of us that we get the right combo at the right time to satisfy our needs.
Note that the best solution combo may involve both Festool and non-Festool tools. This weekend, I'll be posting a review of how to connect a Makita belt sander to a CT22 and attach it to an MFT to have a decent fixed sander for onsite sanding. I also connect my CT22 to a Rotozip for cutting drywall and to some drywall hand-sanding tools for relative dustless sanding (I still do final sanding with a "dusty" Radius 360 round pole sander).
One more point about "onsite". This has different meaning to different people. Right now for me, it means my CT22 and MFT are in my master bathroom during the remodel. The MFT is pretty much core to everything. It's a place to lay tools, clamp in a bunch of different ways, a "routing table", a "table saw", a drilling platform, and a nice place to lean drywall for rasping the edge. My Makita belt sander connected to my CT22 has seen hours of work fixing joists and studs that were installed by less than competent folk. For me right now, "onsite" means having my tool shop and worksite in the same place - a 10 X13 room. I am one happy camper about this.
In a three-four months, I'll be onsite for a couple of weeks helping a fellow frame and finish his new basement. The best combo then? I haven't a clue. Needs change.
Here's a pic of my current master bath onsite workshop:
And here's another at an earlier stage. At this point, the joists had been planed and shimmed (CT22, HL850, Makita belt sander), two layers of plywood subfloor had been cut (CT22, TS55, rails) and screwed in (C12). Note that the plywood had to laid in an offset pattern where the edges landed on joists. They had to be cut to fit with a 1/8" gap between them. Both layers of the entire floor are square to each other but not the walls (walls are not square) and the gaps are precise to within 1/32nd of inch. ALL cutting was done with the TS55 and rails with the plywood laying on sheet foam laid on the floor.
The most they had to be moved after cutting (and sometimes recutting because of the walls) was about five feet. That's much easier than lugging almost full sheets up and down three flights of stairs to cut them in a "shop".
Finally, here's a pic of my CT22 with the arm detached for transportation. (Breakdown time was 1 minute.) For my needs, this works well. For you, CT Mini or Midi might work better. Or maybe one for the shop and longer onsite work, and one for shorter onsite work. Lotsa options:
Again, good luck with your decision.
Regards,
Dan.
p.s., Here's a tutorial on how to post pics on FOG
http://festoolownersgroup.com/index.php?topic=292.0. I think it's pretty good. Of course, I wrote it. 8) I'm also the unofficial FOG picture cop. My mantra is, "Gotta post pics!". ;D