I’m around the ArchViz from 2004. I spent infinite days try to understand light and “emotion” in picture. Before I tried many engines above all Mental Ray, Vray, just a little Brazil and Yafaray.
Now I think that the engine is 30% important in how cool is the final result, considering a lot of work, experiments, coffee and manual post production too
So I use Cycles because is super flexible, free and open source; it is young and I think (hope) it will become faster and less noisy in near future, because that guys works great and fast. I think that today many renders A4 300dpi in superquality are quite impossible in professional times, but it’s ok for tablet/monitor images.
I use the metric unit. Nothing is baked. Baking & walkthrough is quite another workflow-universe, considering that for me postproduction is foundamental. But, Theoldghost, Blender/Cycles is the house of bake, you are at home! In case look for Texture Atlas add-on.
Now…the noise. Arrr… ArchViz/Cycles now in 2016 HAS noise. Especially in large closed rooms. I don’t have a tried method for remove noise yet. In general my current method is 8000 sample, Clamp indirect 30.00, Multiple Importance, large lights and G’Mic addon for Gimp - Repair menu.
(@Naresh: not bad but far from photorealism.)