I rode about 10 miles home once on Vittoria Airliners. I got them mostly for safety after one too many high-speed blowouts, but being able to ride home when repairs fail is a great bonus. It’s the main reason I switched to tubeless, from clincher + latex inner tube.

Any downside to running these?

It is an extra cost, and can make tubeless setup a bit more painful, but otherwise weight and rolling resistance penalties are minimal.

Ok thank you. I figured the downsides seemed pretty negligible. Might try them out on the road bike.

The downside as I understand it is that installing a tube as a flat repair is pretty much out. It's really hard to get the tire off, and even if you do, your options are then to carry a sealant-covered air liner or to chuck it

Yeah. In my 38 years of riding bikes I’ve never had a hole on the road larger than 1/8” so my plugs should be enough. I always worry about flatting at super high speeds in a group so the liner might be a good peace of mind.

Biggest downside is I can't fit the liner and probably the most popular tire range GP5000 TR to any of my wheels without questioning my sanity. Removing bead to put in an inner tube on a road side repair would be near impossible.

Pirelli, Schwalbe, Goodyear and Vittoria tires have been very easy to install and remove with the liner. Schwalbe go on almost too easy and are difficult to seat the bead even with a compressor. I use Goodyear F1 SS for race wheels/liner which have similar specs as GP5000 S TR but less puncture protection.

All this time I promoted tannus which has airliner too and people hating against it here...

Horses for courses. I think the Tannus airless tires are ideal if not perfect for something like a commuter bike, but I wouldn’t want to race in them or do a century ride with them.

they also sell inserts.