Pulling Focus with Alphatron SDI evf vs BMC built inscreen

How much better is it really for pulling focus than the built in screen.
I operate and pull my own focus by eye and w/ the focus peaking feature on the BMC. As run and gun/guerrilla as you can get.

Would using an alphatron evf help me get more in focus results than using the built in screen /w focus peaking.

Thank You for your comments.

In my opinion the LCD screen on the BMCC is almost useless for that sort of work. Especially if you are outside. A proper SDI LCD field monitor or EVF will be much easier to pull focus, as well as critically monitor from. Even the LCD on the GH1 when it came out was better than this.

If you're in a studio, you can probably get away with the built in screen, but outside, EVF is essential.
I was using my Atomos Samurai with a hood in a recent job outside and even that was inadequate.
In really bright sunlight I had to resort to pulling my sweatshirt over my head and camera to get a good look at the screen.
When I was using an EVF it was painless.