shooting at 1.4... just looks amateurish
this is something new to me
For video, going super shallow is cool, but so easily overdone, and has become a 'special effect' with DSLR video these days that's often used too much, with no regards to keeping anything particularly in focus to show off bokeh.
I like shallow, but for subject separation or for a nice dreamy feel when needed, but not for an excuse for poor composition, you can't just keep a single point in focus and ignore how the overall image is composed.
If you need 1.4 for the light, then that's certainly great if IS is part of the package too, but one is better off with a fast wide angle for lowlight video anyways