Actually TAA, Ability One/ETS, and IFF payment/reporting compliance are just about the only things GSA cares about.
With regards to TAA compliance, yes there are ways that companies skirt around the issue, without openly flaunting it. As long as over 50% of the components are manufactured in a TAA compliant country, it can be claimed as the origin. There are some additional quicks to this as well.
Generally not an issue for smaller suppliers, and manufacturers, but certainly an issue where large companies are concerned. Companies do end up being sued/fined on a fairly regular basis.
GSA is primarily a supply system for low level items though. For military applications, the requirements are a lot more stringent.
Overall I think government buyers should be permitted to order products based on price, and quality, NOT based on where the item are made. Fact of the matter is the government ends up spending way more than is needed, and if you were to run an office privately, being able to order from anywhere, you would be able to do so for far less than what our federal government spends.
@DrEvil - About ordering via Advantage, or direct, the fact of the matter is in a lot of cases before an item can be ordered, it has to be made available via advantage.
Additionally, even though you order direct from Black Box, if those orders are placed with government discounts and concessions in place, BlackBox is required to report the sales, and pay IFF on them, so it is still considered a GSA sale.
Back on topic though...