So I was in a similar position to the OP a month or so ago and I went for the DDF40.
My situation was that we needed a new kitchen and for the price of cabinets alone(£2500) I could buy most of the tools I needed to do the job, and numerous other jobs around the house and end up with a great toolset and experience at the end of it.
Well, I've finished the kitchen ply wall cabinets and although I made loads of mistakes and it's been hard work, they still look great! I accidentally used the wrong depth setting on the DDF40 and drilled through some cabinet faces but as it turns out - the wife loves that look so now I have to go and fake the other cabinets too
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My real master plan is to rebuild the tiny 5x7 foot shed (yes, feet!) and turn it into a workshop where I can build synth cases and studio furniture and speakers. So I had that in mind when purchasing tools and it perhaps pulled me in wrong direction for the immediate jobs in hand. You really need to buy the tools you need as you need them.
I already had a TS55 and rail so i figured that if I wanted to build a kitchen I needed a router, a workbench and a jointer. I went for...
Festool OF1010 which is awesome. I've only used it to make an MFT top so far but I'll use it on the base cabinets and doors when I do them.
I built a Paulk MFT bench and it's been absolutely essential in all the work I've done.
Benchdog UK rail square and fence system and various dogs. along with the MFT table, these have been the things that have helped me up my game. The ability to do square, repeatable cuts can't be emphasised enough. And it's still difficult.
Clamps. And lots of them. Clamps for rails, clamps for MFT table, clamps for boxes etc. Buy lots.
Jessum doweling jig. Lovely jig but if you're going to do any volume of work then it's too slow. I'm going to sell it.
Festool Midi vac. I hate cleaning. Having this has allowed me to sand inside the house - something that has previously been denied to me by my wife. Major power up!
Festool RTS 400. Often overlooked model but is reasonably(for festool) priced and very good.Combined with the vac = no dust. Nearly went for a mirka but their reputation is poor at the moment.
DDF40. This was a big purchase for me. I knew I needed something beefy for jointing so it was down to this and the domino. The Lamello wasn't an option due to price and seemed more specialised. I have a vac and festool router so I could of gone for a domino and LR32 hole Drilling kit but the LR32 at £400+ left me cold. I got the DDF40 and 800mm template from DM tools for £999 and I'm very happy with it. It's a bit of a learning curve but it's super accurate and a pleasure to use. I forgot to drill my shelf holes before I built the cabs but was able to easily do them with template and some clamps.
Biggest pain for me has been breaking down sheet goods because I don't have the space . For the base cabinets i might try getting the timber yard to do the cuts then all I have to do is build and finish - in theory!
I have needed a jigsaw and like everyone, I covert the p1cc. All the jigsaw cuts I've done are hidden which is just as well as they're pretty bad but I guess it depends on your project. I actually would get more mileage from a mitre saw than a jigsaw so I'll probably go for the Makita 1019 or something.
Hope some of this helps in your decision making.