I have one of the new Intel drives and was looking forward to this firmware update to enable TRIM.
Thankfully I missed the fact it had been released, so didn't get to know about it until these problems started cropping up. So I won't be ugrading the firmware until this has been thoroughly researched and fixed by Intel.
Interestingly apparently TRIM only works if you are using the Microsoft AHCI drivers - I have 'upgraded' to the Intel IMSM v8.9 driver already, so even if I had upgraded the firmware TRIM would probably not work and the only way to optimise the drive would be to manually run the optimisation tool - maybe Intel should have timed an IMSM update as well before doing this?
This episode has also justified in my eyes the decision I have now taken to split my drives, with the OS on the SSD but the data migrated to a seperate HDD. So, if I lose the SSD I only have to reinstall the OS and programmes, and not worry about the data.