They don't filter quite as well as a good paper oil filter. If your going adventuring round the world, it would be a good choice. We also use them in some race bikes where oil flow is a concern, as they are a bit less of a restriction to oil flow. In general though, a paper filter will give you cleaner oil.
Among the paper filters, avoid the Fram. The HiFlo, and K&N (Made by HiFlow) are among the best.