Like Jim said above, bamboo cabinets are just $200 more than the ones made of MDF. Plus bamboo can be stained in any color you want .. so if you like walnut, then use a walnut stain. I'm sure they'll look just as great. Or use caramelized bamboo ply .. they are much darker and have killer looks!
To me apart from the looks, a huge selling point of bamboo is how stiff and inert it is. Though Jim has not taken sides on this, you can read what ascend acoustics had to say about using bamboo to build cabinets. They conducted some tests on cabinets built with bamboo and MDF and found that bamboo was way better. Bamboo is harder than maple and has more tensile strength than steel!http://forum.ascendacoustics.com/showthread.php?t=2597
Plus bamboo being grass is a lot more environment friendly. If i ever decide to splurge on speakers again, it'll be on a pair of STs in bamboo.