I wanted a 16” with the intentions of putting a suppressor on it. Haven’t done that yet, BUT, when I bought mine (Adel Outfitters had both) the 20” seemed to balance way better, and after having a Ruger American 16”, I was looking for a bit more heft (the 16” Tikka did feel lighter than the 20”).
I figured if I do get a .22 Suppressor (and I’m dumb for not already having done that), I can trade rifles, trade barrels, get mine chopped, or just deal with an extra 4”.
Honestly, I think it’s hard to screw up either way.