How do get back to FC Pro X 1.4

The easiest way is to have saved a copy of the older version, for yourself. (I always .zip the old version and store it before installing a newer version of FCPX.)

Beyond that, it's hard, as the FCPX app is licensed to YOU. If a third party were to send you an older version, it would not work without your license number. And... I certainly can't comment in this forum on how to defeat that. 😉 Sorry.

"Slow down issues?" Check here: http://www.finalcutprox.guru/FinalCutProX.guru/Blog/Entries/2015/4/16_FCPX_10.2_ Performance_Report.html

Only if you have a backup of the old version and of your library with events before they were updated by FCP 10.2.

(After hearing of some reported problems with AVCHD clips in FCP 10.2 I made sure I had this before updating 'just in case'. As it turned out there were no problems with 10.2 nor any slowdowns.)

I think it may be better to investigate why you are getting slowdowns - can you be more specific?

Geoff.

Perhaps the contributors to these discussions can help you sort your slow-down. Please provide your system specs and your FCP set-up.

Is the poor performance found in all projects? what kind of media?

Russ