used it for about five years in three sets of tyres DO NOT put into the tyre more than stated on the chart,it does extend tyre life as they run cooler,
it does not unbalance the wheel or effect the handling or grip, make sure your local friendly tyre fitter knows that you have fitted ultra seal some will refuse to change tyres or charge more.
Check your tyres often for nails ect as it will seal around it if you find one mark where it is ride 1/4 mile pull it out ride another 1/4 mile to allow centrifugal force to seal the hole the ultra seal forms a permanent repair check tyre pressure as you will get a small loss.