If you have a better SB, replace the old ones; especially if you have a "store" or it fits your style of play better
The question is not, 'do you replace the bridge' but is it worth the Store Building. If you don't have one or aren't willing to use it Then I'd probably say no even if you have a better alternative. That building should be around a long time before a better SB shows up. Then when it does there's a whole lot of SBs that are hitting hitting the AD first.
I loved my Dark Tower, coolest building, in FoE, ever...gone. Fully leveled Tholos is next. I'll try to save both contestants estates but if I can't place the rotunda and the 3 carousels...gone.
The only SBs that wont get replaced; are the ones that provide Attack bonus that is not easy to get. Even if you're not a fighter.