Theoretical: SoHo/Small Business 5ghz Spectrum

In your personal experience, and in theoretical "best case" scenarios, which is preferred:

a) 5-6 clients on 5ghz with high-bandwidth use connecting to a 5ghz AP through an ethernet switch to the AP via a single 5ghz router/wifi bridge. Assuming the router is of high quality. b) Those same 5-6 clients on 5ghz directly connecting to the AP using whatever adapters they have on-board.

Now scale a) and b) from 5-6 clients to 15-20 clients. Same result?

There will only be a single 5ghz AP in this scenario.

(I'm trying to figure out cost/benefit for an upgrade I have coming up.)