These shirts are a great buy. They fit well and the material is surprisingly thick as compared to other undershirts. They're slightly irritating until you wash them, but most clothing is like that.

These shirts are fantastic, and the price is right!

EDIT July 30th, 2010:

So, I've been wearing them for a while and they've still held up very well. I'm outside a lot where the heat index is usually around 100 degrees to 110 degrees Fahrenheit and there is no sweat staining of any kind. The "tagless" feature is proving to be much more comfortable than I originally thought.

I remain satisfied with my purchase!