I have a seersucker suit, but I only wear it as separates. I can rock it pretty hard in individual pieces, but I feel costumey when I wear it as a suit. One day I might give it another try, as I've acquired a bit of confidence with age, but I've yet to follow through. I will say some guys can pull it off really well. I seem to recall FLMM (or possibly Mrs. FLMM) posting a FB picture of him in a full suit, and it really worked.
Yeah, some people down here seem to think the first day of spring is some sort of demarcation point for breaking it out. I have an Atlanta friend who posted recently on Facebook insisting it's appropriate to wear his seersucker because it's now spring and "wedding season." A bunch of us tried to explain that it's too early, but he'd have none of it. We eventually just had to give up and let him be wrong.