It is a little bit grainy in the full size view. Whether it is acceptable or not depends on the purpose. If you must produce plenty of renders during the process of developing the architectural concept to show and discuss several step of the evolution, than this is very fine, because it is an interim product. It also works better and has less noise if it is reduced in size.
As the final render for a glossy brochure it won’t work, of course 
Well then I think it would be acceptable, since the use would be for printing several renders on a presentation sheet together with vectorized drawings, in rather small size, perhaps 10-20cm wide. When I get more revenue I can get a better GPU and produce cleaner renders 
Reduce the contrast a little bit.
one nitpicking, trick with replacing window by emission is always looks bad, as light decay 1/(distance*distance), and you get very visible innatural wrong hilight area very close to window, there must be proper light portal or special light for that.