Quote - Less than you may think. I rarely render over 1024 max texture res. I never go higher than 2048. Shading rate at 2.00. No filters. No smoothing unless it's close... RayTrace bounces at 0.00-1.00 unless there are mirrors or a closeup. Pixal samples at 3

RayTrace ON
Shadows ON
Use displacement maps ON

rendering a 4096 pixel texture at 1024 max texture res destructs 3/4 of the detail and saves very little time on a render.

with a min. shading rate at 2.00  you basically blur and pixellate the rest of the texture into oblivion. while it works OK in your render because its sortof a low contrast low-lit render, this would completely destroy a face texture.
yes, with a shading rate set to 2.00 you are rendering much faster -- but thats mainly because you are dumbing down the textures to nearly the detail level of a simple flood fill.

its all about compromises. i would rather wait 2x as long for something to render and have all of the detail, than to render half the detail in half the time. i bump up the shading rate to 2.00 or even higher for quick preview renders, and reduce the pixel samples to 1, but i will never render a final render at anything but 0.00 shading rate - which is full detail. lately, because i do not like the pixellation along the edges of the body, i have even been rendering with 18x antialiasing.

different strokes for different folks, i suppose. some people are more interested in speed. i am most interested in every ounce of realism i can squeeze from the firefly renderer, and if someone is going to spend weeks painting detail in a texture i want to render all of that detail -- if youre just going to destruct the texture to 1024 max size and 2.00 shading rate then you might as well just use simple freebie textures since there will be little difference in the final result.

give me a minute and i will illustrate the difference between something at pixel samples 3 and 18. in fact i think for my next big render im going to try 36, because i still notice jaggies along the thighs, etc.

i have 2 computers so i can afford to tie one up in an hour long render. but if i didnt, or had a slow computer, i would simply do what i did before i had dedicated rendering machines -- i would do all my preview renders and set up a scene the way i liked it, and just hit 'render' before i went to bed. even complex MAX renders with global illumination are done in that period of time. its all about what is important to you. speed is great, sure.. but if im going to make something i will post in my gallery then why not spend an extra hour rendering and get more detail out of it? i never compromise when it comes to quality. 

great tutorial btw. dont get me wrong - i am not disagreeing with you simply offering my alternate viewpoint concerning render detail vs speed. different people have different priorities, perhaps someone who only has an hour of time for poser every day and shares their computer will obviously place speed as a priority over quality. i do this for a living so i am generally here all day, so i have different priorities.

cheers,
-gabriel