I’ve got them. They lower the back of the seat quite a lot, but don’t lower the front as standard. You have to disconnect the front height adjustment for that. I’m 192cm and they work great for me. I really like that only the back is dropped as I get loads of thigh support. I’ve never felt uncomfortable and I’ve now got room for a helmet with the top up. They don’t slide back and forth quite as smoothly as standard, but work very well given the tiny clearances. They’re a bit of a sod to fit by all accounts, which is why I paid my local MX5 specialist to fit them for me! They swore apparently. Bottom line is that I now sit in the car rather than on it, which is great. I’ve bought a booster cushion for anyone else who needs to drive it.