Saw recommendations for a hobbyist

If you are working with sheets then the MT55 makes sense.
If you are doing you cabin with real wood, then maybe a table saw is better.

The used Festool market is absurdly high, which is good for you.
I have a MT55 and rate it highly. The tracks are better too, and the Bosch or Mafell tracks are the same and the saws fit on either one.
I put the MT55 onto an MFT sometimes, but more often on a foldable table.
I have heard all about the skill and technique required for using a TS55.
It boggles my mind.
I pick up the MT55 and go at it hard, with no special skill required other than setting down and clamping the rail and keeping my paws away from the blade.
If you can sell the TS55 then maybe you consider that route?

Secondly.
You may be better off with a rebate or dado than a 45 for strength. There is almost no way to press against it that does not want to try and slide the joint.
And biscuits, dominos or dowels in at a 45 require more $, £, or złoty to make happen accurately and quickly.

There are also router bits which do a 45 degree angle with a jog in the joint... Again more $, but there are a few ways to get the results.
Most of them are good, and depends on what you prefer... Or what you have.

Thank you for your thoughts holmz. I’m working with sheet goods, so MT55 would make sense. I think selling Festool for a good price won’t be a problem, I only got it a few months back. I may try sending it back to Festool, as I’ve been in touch with their support about my problems.

I expected Festool saw to work as you describe MT55, set your angles and go, but there is more to it. Support guys from Festool suggested I “may be putting too much pressure on the front handle than is necessary causing the tool to `tilt`”. To me it translates into - too much room for error.

Thanks for the tips about the 45 joints. I’ll have a go at a rebate joint next. A router and domino are on my shopping list, but can’t get it all at once!

I also have Festool midi extractor and I’m happy with it. Do you think I can carry on using it with the Mafell? I quite like the auto switch on it too. Presumably this would work the same way with Mafell?

Heiko, I think the version you mention is the same model I have. There maybe ways of using it to get good results, but I'm struggling to find them. I wish I could take out MT55 on a trial basis, but I don't think Mafell offers that. On the other hand if you buy either Festool or Mafell you can sell it used for good price if you don't like it!

Pawel, the midi vac will be fine with Mafell.
Cutting long mitres can be very tricky, and requires sound technique. Keeping the rail flat, keeping the saw flat, not pushing the rail sideways whilst cutting, etc. The extra clamp slot on the Mafell rail, closer to the cut line, helps a lot.
I always try to cut a mitre with two cuts - the first one to remove the bulk of the material, a couple of mm oversize, the second one to trim the first cut. I'd suggest practicing before selling and changing saws - even though I have got much better results mitring with my MT55 than I ever got with my TS55.
Lincoln.

So where are you at?

I bought my MT55 from Germany and shipped to Australia, so I was pleased it lived up to my expectations.
It is problematic to return stuff.

I think any vacuum would work, as when the hose comes off you know something changed pretty quickly.
And it rooster tails the dust out the port like a waterski boat with no hose.
Just plug it into the midi and go at it hard.
The Dust deputy might be helpful as most of what comes out of the saw is more chips that fine sanding dust ??

I am a hobbiest too, so I do not believe you need any innate skills to use it.

I got the last of the LO50 Mafell routers. Not sure if it fits on the Bosch OFA Kit 800 rail adapter, and I am not sure that would do a good job on making a slot or not. But the LO50 works good for a 1/4" (6-mm, 8-mm) router. I believe it fits on an Erika table, and I know that the bigger 1/2" LO65 does. Whether that is important or not I do not know.
Everyone raves about Bosch and Triton routers too, but I do not know the good from the bad, and everyone says that they are good.
However the LO50 is working well for me for freehand/template work. I am pretty sure if I get a 1/2" router it will be an LO50 so I can use it with an Anada jig... But that is not too certain.

I should probably try doing a slot with the LO50 and the rail adapter.

OFA Kit 800

Maybe 10-mm bit to get out the bulk, and then put in a 12-mm to dust off the sides and bottom ?? 
Would this work??
If the slot is close enough to an edge then there is a router fence - so that might work well too for a rebate or dado, but not for a 45 degree angle ??

You will struggle no matter which track saw you have. Long miters over 12" are extremely difficult without a sliding table saw. Especially if you are mitering boxes which require 4 perfect angles in all directs.

You will have to be patient and build a system that gives YOU the best results.

So I did it! My MT55 arrived yesterday. I ordered it from Germany and it worked out more or less the same price as I paid for the TS55 in the UK. 493 euros for the saw, 160 rail and an extra blade was a very good deal I thought... See www.lefeld.de/mafell-tauchsaege-mt55cc-mafell-max-f160-2blaetter.html if anyone is interested.

I do like the look of the mitre joints, so I’ll carry on trying and see what I can get on MT55. Mitres or not it should be easier to get results I want. I'll let you know how I get on, but even just looking at how the same functions are designed, Mafell looks like a more refined product. They are actually quite different, more than I thought they will be.

Do I need to trim the splinter guard on the rail as with Festool? There isn't any mention of it in a manual.

Just set the blade for a scoring cut (with the little lever on top) and then run it on a board.