Stan's here, no problems. It seals well with some tires (like Maxxis), not so well with others (like Schwalbe). I put 2-3 oz in each tire and it lasts about 12 months. But on MTB only.
On the the road bikes, I use inner tubes, with no intent to go tubeless as I see only disadvantages in that application.
NOTE that Stan's racing sealant recommends replacing far more often, weeks instead of months.