Share your experience!
The default security settings in the J don't actually provide a "no lock screen" option or any analogue which would take it straight to the home screen when the on button is pressed. I'm wondering if there's a feature for it in the settings or, failing that, a third party app for it. For some reason it's hard to find apps that remove functionality 
Thanks guys!
Settings-security-screen lock-none.
That option isn't there, that's my problem.
Strange,check if the same thing occurs in safe mode:
http://talk.sonymobile.com/t5/FAQ/How-to-boot-your-phone-into-safe-mode/m-p/348008
At least you should get slide,is it there?
Nope, even in safe mode there's no "none" option. Slide is there, and I can keep using that if there's no solution, it just seems really weird.It's running Android 4.1.2, and the build number is 11.2.A.0.31.
I have an older Xperia P and if I remember correctly,it was able to use none on 4.1.2.
Oh well \m/
I'll stick with slide 
Just to get more info,contact xperia care about this:
http://www.sonymobile.com/global-en/support/contact-us/