Everyone say tire sealant is useless, is it real? Shall I use tire sealant?

First I shall say every product out there for a reason, if it is of no use, they vanish. QB tire sealant working temperature can be adjusted from -45 to 90 ℃ depending on customer’s needs. so it is not right to say it can not be used in cold areas.
Our QB tire sealant seals tube up to 6.8mm, motorcycle tubeless up to 10mm and car tubeless up to 18mm.
To be objective, when you apply on tubes, the sealing performance really depends on tubes, I have a bike came to punctures twice in one week, I changed the tube but got punctured again. so I tried our own sealant and turned out it seals very well, the tube is up with pressure maintained well for months, no more leaks, but it feels a bit heavier than an empty tube, anyway, it is normal since you put extra weight inside the tube.
But for motorcycle, tube sealing performance is not as good as bicycles, because when you are driving, bicycle tube is larger, the tube will move inside the tire resulting in the moves of the sealing plug, so sloe leaks could happen. that is why for larger tube, tire pressure maintained at a less-better performance.
For tubeless, QB tire sealant seals the leaks permanently, not need to go to repair shops, stay valid in the tire for 6 months during which time, it seals every puncture within the sealing ranges.
As for vibration problem occurs with 4 wheelers, it is common problem for all water-based tire sealant. We tested slime, ours and other sealants, turned out all have effects on car balance when speed exceeds like 80km or 110km, depends on car type, volume installed. we have detailed test reports. for two-wheelers, not vibration issue.
So, if you are driving at high speed and the road condition is good, rarely got punctures, you do not need tire sealant.
For those driving at moderate speed and got punctures often, tire sealant is really a good choice, since it saves you a lot of time and trouble.
Tire sealant is different from other repair products which see the results immediately, but with tire sealant, you won’t notice when it seals the leaks, only when it failed to seal (because puncture is larger than sealing ranges), people notice it, so the feedback received is almost negative, because you won’t give feedback when it seals.
QB tire sealant won’t advertise as a 100% effective god like products, we tell people all pros and cons before they buy. we only sell to people who see this product objectively and accept its value.
So tire sealant is not a solution for all, but a solution for only those people who found it really helps.