I just posted saying it had sped my laptop up. However now I restarted well, in short I have a £2000 paperweight. Every app freezes, doesn't respond, it won't connect to wifi, login is slow as hell and it won't even shut down without holding power button. It's rendered my computer useless. I also keep getting these messages saying programs need to access my keychain which aren't minimisable. I am doing this via my phone!