Thanks, yes I’ve come to that conclusion that I need to go and try them before buying. I need good back and arm-rest support so need to find out if it’s worth spending the extra getting ‘4D’ ones but only trying them will tell.
It’s very similar. Honestly, for the price I wasn’t expecting much but it held out really well and gave a good few years of service (and may still do, it went into the reuse section at the tip)