With tubeless tyres your rolling resistance is lower. Also, they are more comfortable because they allow you to ride at lower tyre pressure. In addition, as smaller punctures are automatically sealed from within, you are less likely to get a flat tyre. The disadvantages include the fact that these tyres are more difficult to mount and require more maintenance than tyres with inner tubes. And if you do get a flat tyre because of a larger puncture, it takes more work to put in an inner tube or to repair the puncture.