Now that the KO3 is available for the 19” rims, any thoughts on whether 20” is still preferred?

 

It certainly provides a valid option for 19’s, which is helpful.

I like to upsize my tires and run 33” ko2’s (bought before ko3 came out, I do 275/60 K02's w/ a 1.5" rod lift) IMO it’s a great tradeoff, its bouncy in offroad height from the rods but otherwise feels very stock to me.

I’d want the same on a 19 to get more sidewall. Whatever size would get me to a solid 33”. But alas. No dice.

 

The 19” will give you 1/2” more sidewall. Otherwise they’re identical.

The 20” wheels still have a lot more options for tires. But strictly comparing KO3 - the 19” will be better for off-roading because of the sidewall. Might be offer a tiny bit more comfort, but since they both carry an E load rating, they’ll be on the stiffer side. My E-load rated 20” Falken Wildpeaks are nowhere near as smooth and comfortable as the OEM 19” XL-rated Goodyears just because of the construction. E-rated tires are designed for trucks that carry heavy loads, hence the stronger sidewall which sacrifices ride quality.