Like you, I started with a full-size keyboard. Since then, I have tried 60%, TKL, and various form factors and layouts in between.
Regarding form factor, I prefer 60% or TKL, but nothing in between.
With respect to layout, I prefer the HHKB, which is now my daily driver. When I am using other keyboards, I use remapping software (such as ATNsoft Key Manager) to remap them to something as close as possible to the HHKB layout.
As for switches, I have tried every flavor of Cherry, various Alps (including Matias), IBM beam spring, IBM membrane buckling spring (Model M), IBM capacitive buckling spring (Model F), Space Invader/Angry Bear, and various vintage linear switches. I would now rank my currently available switches as follows:
Topre 45 ~ Topre 55 ~ IBM Model F > Brown Alps > Matias Click > Matias Quiet > IBM Model M > Cherry mx (and clones)
Within the Cherry mx family, clears were my least favorite because of the steep increase in force past the actuation point -- I found this tiring, because I like to bottom out. Some people like this, because it encourages typing without bottoming out.