In reply to Bjartur i Sumarhus:
Road bikes and tubeless tyres = massive PITA. If you get anything other than a teeny hole, the sealant will spray everywhere, your tyre will pop off the rim and you will be back to wrestling with a tube covered in slime. If you run them at the much vaunted lower pressures, you'll hit a pothole, cut the side wall and then see above. Even if it does seal, you'll still be there with a pump trying to get some halfway decent pressure back into it.
I've just thrown £120 worth of Schwalbe Pro 1 in the bin because they are a waste of time effort and money and gone back to Michelin Pro4 service course which are usually on sale for £24 somewhere. The added plus is the Michelin stick to a damp road whereas Schwalbe will stick you into a ditch given a chance. Only 10 minutes to change a flat with Michelin, and you can put the tyre back on without a lever. You'll not be doing that any time soon with a tubeless tyre. Plus CO2 is no use with tubeless - it just blasts out through the hole, so you need to carry a pump (and a spare tube wrapped in clingfilm and gaffer tape) shoved under the saddle.
I went off on a two week trip and spent every day refitting tubeless tyres. I got through a whole big bottle of sealant. I ended up with patches on the inside of the tyres to seal them. That only lasts a while because the liquid rubber dissolves the vulcanised patch seal. The following year, with Michelin Pro4 - nothing, just kept on rolling. After 3 years, enough is enough.
Mountain bikes - different story.