Each to his own!The "sunken look" is minimal with the 21s but it's a bit more noticeable with the 19s. The 265/295s on the 21s compared to the 255/285s on the 19s make a slight difference. When I parked next to another Plaid with 21s, the 19s on my car seem to have a little bit more of the "sunken look." It's not really an eye sore but I'd still like to get my 19" wheels flush without changing tires. I'd have no concerns putting 15mm or 20mm spacers on my car as long as the spacers are hubcentric and made specifically to fit the Plaid. Also made with the strongest aluminum.
I have the 20's from an X and they are wider than the 19's