Macbook Air display lag after EFI/SMC updates

I own a Macbook Air since last September and I've experienced this issue before. After some EFI or SMC update (not really sure which one) my computer display is TOOOO slow and really unusable. This behaviour is more evident with Safari scroll or switching between desktop windows. In the previous situation the problem was fixed after an additional EFI or SMC Firmware update (later in the year). The current situation is that I've updated my MBA last week with an additional EFI/SMC Firmware update and the problem reappeared. I think it should be related with these new updates. I've also tried to reset SMC and NVRAM/PRAM and the problem persists.Does anyone had this kind of problems with MBA 2013 with latest updates?

Thanks

JCABRITA