CPU spike and beachball in Logic Pro X since upgrade

Hi all

I know I shouldn't have done it so soon, but I upgraded my OS to 10.11.3 latest El Capitan.

Now, I seem to be having a lot of trouble with Logic Pro X. Particularly with CPU spikes and stuttering playback to the point of unusable.

I could open and play songs fine under Yosemite, but now the same song just won't play under 10.11.3 and I'm forced to use Freeze function on many tracks to get it to play. Not great while mixing etc.

I have the 24th Jan Logic Pro X update, but it doesn't seem to have helped. I still that beachball a lot, and CPU spikes are driving me crazy.

My Mac is Mid 2012 MacBookPro Retina 15" 2.6Ghz with 16Gb RAM. Surely I should be getting better performance than this?

The same song just won't play as it did under old OS.

I feel a fool for upgrading really, even though I did run it as a test system on external drive and all seems OK before making the jump.

Wondered if there's any tips or help out there?
Or is this a known issue that Apple are working on fixing, because at the moment, I see little benefit in the upgrade to 10.11.3

Thanks all