At club level I wouldn't be too concerned, we're very much a 'run what yer brung' kind of club. If however you want to go further afield then other tracks may have issues with capacity.
Having said that, capacity alone won't necessarily give you a vast advantage, other aspects of engine design potentially make bigger differences.
I think BRCA rules are that if its a RTR car with an engine bigger than .21 its OK, like the hyper 7 tq .28. As phil said though, I dont think anyone will be too bothered about you running a .26