@nifflerUK You’re on the right track - especially your comment about resale value. This level of equipment holds its value incredibly well, and if you do decide to sell it once your project’s complete, you’ll get back a hefty chunk of its original cost, especially if you’ve kept it clean and nice. I bought a 5650CV 5mm Deros five years ago and I absolutely love it - it’s just superb in every way. The nozzle on the machine’s also a direct fit on the end of a 27mm Festool hose, it comes with both 125mm and 150mm pads, and the speed is fully variable.
Their Abranet idea was genius - the entire sanding pad is vacuumised with a large number of holes, and the dust is constantly sucked through the net across its entire surface area. I know that the initial cost is a choker, but for me, it was one of those purchases whose price was forgotten inside a week. For a house renovation, it’s also worth mentioning the fact that there’s a ‘savage’ HD version of Abranet available in 40-grit which is great at stripping paint from door frames, skirtings and so on - or at least removing all the high spots and surface imperfections quickly, before swapping over to something like regular 120-grit for final smoothing before paint. I can’t comment on the hand sanders because I don’t have one - all my corner sanding is done using a triangular pad on the end of a Fein multi-tool. There are plenty of in-depth reviews of the Mirka on YouTube.
There are many folks on here with a wide experience of the Festool sander range, so maybe someone more knowledgeable could chime in with advice on the best machine for your application as an alternative.