If I really like a character, I'd stick with em.
I mean, SFIV Sagat is full on S+ Tier, no question. Strong fireball with excellent recovery? Super strong uppercut that does so much damage and at worst, trades in your favor? Tiger knee loops? das mah mayn mang.
But then SSFIV came out. Oh boy. Sagat, you seen better days. Nerf to damage, fireball and TK recovery increased. Sagat at best is B-tier in comparison of others (Guile, got massive buffs you sonuva *****). Couple with some really bad matchups (Guile, Akuma), Sagat ain't so. But I kept with him and to make up for changes, I developed a more aggressive and frame trap heavy kind of Sagat. When I went to locals or whatever major that came up, a lot of people were impressed. TLDR; Character specialist won't drop their characters anytime soon.
Right now I'm in a crisis of playing between Sheik, ZSS, Marth/Lucina, Captain Falcon and Regular Samus. Not because they're high tier but they're so much fun.