Hoo boy, this is like battery vs. track power.
I've spent 20 years posting and reading on forums, and in general, COMPLETELY fixing track to a SOLID base does not work.
Free-floating track in ballast is the most successful in terms of not making kinks and track misalignments from heat and cold, but the natural movement of the track will make you re-ballast every so often.
Fixing the track "every so often" has worked for many people, basically fixing the track in a few places to keep it from moving a lot, seems to work for many people, and seems to provide a balance between large migrations of track and the other extreme, ripping the rails from the sleepers when the sleepers are not given the ability to move with the rails.
Another issue is what happens with ballast. If you try to just lay track on a hard surface, ballast will work it's way underneath and raise the track with the natural expansion and contraction every day.
No hard surface and this is no problem. Trying to stop the ballast getting between a board and the track forces you to try to fix the track down firmly everywhere, and now you have expansion problems with the rails.
Something that works for people is a little glue or cement in the ballast, so extreme forces can move the rails but small movements are constrained. This is good for people who want to free float their track, but too much rain washes the ballast away.
My personal method is using coarse ballast (unaffected by rain) and free floating. This has worked well for about 20 years, I can spray with a hose and not disturb things, and the track stays in alignment for years at a time.
Greg