If it works for you and gets the job done, why not? 🙂
I have not tried it yet. I'm wondering if it would be likely to do a decent job.
I think it'll depend on what yor expectations are and how much time you have to encode. A lot of the workload is offloaded to the GPU during editing. So long as you don't get to crazy with your edits (lots of overlays and effects) and if you don't mind waiting for the video to encode I'd imagine that it'd work really well for 1080P.
That said I wouldn't seek one out for this purpose. If you're going to buy it, then there's way better options out there.
Is it an 8350 ?
If you've already got it? Sure, it should be able to suffer through. It will all but certainly be slower than a newer system.
If you're building a system for this purpose specifically? I absolutely would not recommend that unless you're picking it up for **bleep** near free.