Yet !I have 4 of them and use them all the time on my RRC LSE. They've not squashed me yet.
No I hadn't that is why I posted the question, I don't know anyone who has any so thought best ask for opinions.They wouldn't/couldn't sell them if they didn't work. There would be a bit of bother if folks were getting flattened all over the country. But it seems like you've made your mind up ...
Just to add, I bought a pair of 3 ton ones from Toolstation, there fine for under the axles as they arnt very tall, ended up getting a pair of 6 tom stands from machine mart for about £38 - bit more expensive but I have them on the chassis of my S3 at the moment with the rear axle off.Thank you to everyone for their advice, I am now convinced and will be purchasing a pair this weekend.
Cheers John