Yes, it’s really good.
I looked at Buttkicker to start with but decided initially to do a DIY job and buy a separate amp and base shaker and connect the shaker to the PC table. I’m by no means an expert on electrics but managed to get it all fixed up and working in no time. It’s actually way too powerful and I have the settings turned down to something like 2.5 out of 10. Too high and the vibrations come strongly through to one of the rooms below. I adjust the settings upwards a bit for jets and downwards for prop ac.
It certainly adds a bit more immersion to the sim experience. I might look at Buttkicker for the PC chair at some stage. Hopefully, the floor won’t collapse! 