I've never done it side by side, but I've used a 200S amp through a 2000S cab and vice versa. I think the 2000S cab sounds "bigger", more bass response and overall deeper, maybe even a little louder.
And, it looks so much better than the 200S cab under a 2000S head. Balanced, not that goofy "T" shape that a too small cab with a too big head gives you (one of my pet peeves).
It's also exponentially more of a bitch to load in and out, the extra weight and 6" all around can turn a simple gig into a project. 20-30 years ago I wouldn't care, but now I wouldn't schlep a 200S head with a 2000S cab unless it was my only option, I'd just crank up the bass control to get that "thump".