Nato sides/back on my Yamaha FG 720,...no complaints here.
http://en.wikipedia.org/wiki/Nato_wood
http://www.musiciansfriend.com/document?doc_id=99234
Nato, also known as Eastern mahogany, has a warm resonance, is very strong, and is often used in the necks of less expensive electric guitars because it's not as costly as mahogany.