You sound a lot like me, in terms of projects.
I have the CXS, TXS, and C18. The only one I can’t live without is the CXS.
The C18 is also very good, I use it primarily for drilling holes. I like the C series for the handle shape. Makes it easier for me to drill straight.
The TXS I got on a whim because I loved the CXS so much. I don’t use it that often, but it’s a fine drill too.
For the heavier duty stuff I use the Milwaukee Fuel Surge line, as I’m pretty locked into that battery platform. If I had to start all over again, I would go for Makita, particularly that oil impulse driver that
@usernumber1 mentioned.
Anyway, I would start with the CXS and save your money for other Festools that aren’t drills. Remember you will need to buy all the centrotec bits, your standard hex drill bits won’t be compatible. And there is no socket bit available (unless this has changed for 2023?), so you’re probably going to need a non-centrotec driver anyway for things like deck work (ie driving endless Simpson strong tie screws into joists). There is a socket converter available (I have it somewhere), but I find it easier to just reach for the Milwaukee whenever I need to drive a bunch of hex head fasteners.