I've got a 13' MBP 2012 pre-Retina running Yosemite with all of the latest updates that I'm about to put a sledge hammer through due to how much pinwheeli...ing I'm seei...ng. I upgraded it from Mavericks and I'm really regretti.....ng the move. It's pinwheels on a wh...im. Sorry, it's havi...ng yet another moment of beachball madness. There appears to be no rhyme or reason to it happening. I have noticed that sometimes when using Firefox I get a lot of script errors that bizarrely seems to stop the entire system and send it into rainbow frenzy of non-productivity. This is worse than Windows hourglassing. At least with those I'm generally able to open other apps and proceed. With this I'm just stuck wanting to put my fist through the screen while my Mac seems to want to declare it's LGBT friendly every minute. I have 4 GB RAM that hopefully will be upgraded to 16 GB by the time Santa squishes through my non-existent chimney, but considering I use Logic to produce music and it barely shrugs while sending huge amounts of things through the CPU and RAM, I suspect this isn't the cause. HELP! I should state that I'm technical and work in IT, but am largely 'new' to the Mac way of thinking, so I'm all ears for suggestions. I've scanned for adware and came up blank. Ccleaner doesn't report that there's much to clean and my start up doesn't have much that boots upon start. I've read a decent amount on the Internets and ran 'sudo update_dyld_shared_cache -force' to clean up the DYLD cache, but that only seems to have improved things a bit. This machine is far too nice to end up with a sledgehammer bowtie.