I am 6.1 (185 cm), but I have small hands - used a 4 3/ 8 as kid (on a Prince Graphtech DB 90), but switched to 4 1/4 for my next racket(s). When I was no longer playing regularly, I used a Head Prestige Tour Team with a 4 1/2 grip with an overgrip. Now I buy all my rackets at 4 1/4, and I put on an overgrip (Solinco Wondergrip). I especially like the oval Head grips, definitely more than Prince grips (my current main rackets are a MG Radical Pro and a Prince EXO3 Tour 100 18/20).
To me, 4 1/4 feels more comfortable because I can change from forehand to backhand faster. Never had any wrist issues.