First off, I must confess, I find myself becoming somewhat of a Mafell fan after replacing my TS55 & Carvex with the MT55 & P1cc. But this is my honest opinion on it.
The only negative things I have to say about it are:
1st, there's very little information available.
2nd, there's no dust collection capability when using the tilting baseplate.
3rd, there's no LED light on it.
4th, Mafell doesn't have plug-it leads on their tools.
5th, it's expensive.
When it comes to build quality, power, cut quality, dust extraction & all round performance, I much prefer it to the Carvex 400 it replaced.
In the end it's still just an (expensive) jigsaw though, but I must say it's the best I've used up till now.
For what it's worth, I find that in general (there's always exceptions), Festool is ideal to work with and more suited to a shop enviornment. I'm not saying there not suited for the jobsite. I mean compared to eachother.
Everything complements and works nicely together and there's tons of accessories available for just about every tool. And there's dealers everywhere when you need something.
Mafell mostly caters to a different market than Festool. There's very little info, not many dealers and they have less but more specialty tools. Their KSS saw line-up for example can be a huge time savings compared to going back and forth to the miter saw (depending on the work you do of course).
I do find them nicer to work with on a job site, out on location. They've always got more power, feel more resistant to wear & tear and they pack the accessories more compact into a single systainer with the tool. It gets done faster with Mafell.