I have 3/4" prefinished brazilian cherry installed in a home office. For the area where the chair rolls around I was planning to buy a smooth plastic chairmat (no carpet spikes). However there's a technical bulletin in BR111's web site that states "do not use rubber, foam backed, or plastic mats".

What would you recommend using?

I recommend to my customers to replace the plastic casters on the desk chair with rubber wheels, and no mat.

Yup, those plastic pads will prevent your floor from breathing. Simple matter to get replacement wheels from any office supply store.

Check online and with your local office supply store...more and more companies are offering hard mats made of natural, "breathable" material just for use on hardwoods.

I have never heard of a "breathable" chair mat. Did a search and its amaizing on how all the results including office supply dealers sell "mats for Hardwood", and their all plastic materials ! Their all selling a bunch of time bombs.
I found one place that offers a "Vented Chair Mat", and no price. I think I'll give them a call tomorrow. That would be a great "add on", as an option to rubber wheels.

http://www.chair-mats.com

I know there are companies that offer bamboo, wood, and cork mats. Usually with a cloth or felt backing that would be suitable for use over hardwood. They aren't inexpensive, but cheaper than replacing a floor!

Yes, I saw Bamboo "roll up", and Wood mats. They just look pretty cheesy. I question how they will look on a nice wood floor And rediculous prices. Didnt see any cork, of coarse cork is non porous. Since I'm inbetween jobs, I'm gonna continue checking it out. Either that, or the honey do list