opinions on Sigma 50 1.4

Hey guys i currently have the canon 50 1.4 and just wondering if it's worth selling it and getting the sigma instead....

I read on canonrumors that mk2 is coming and I want to get rid of mine before it comes out...

so should i wait for mk2 or just get the sigma now? Only problem is if i wait, my lens will definitely drop quite of its resale value...

Also any known problem with the sigma 50 1.4?

I am kinda scared of getting sigma lenses tbh...