That's hard to say. I use Workman, because the focus on digraphs really meshed with me, and I like the feel of it.
It definitely took a solid effort to learn another layout, especially since I spent the time choosing a favorite. I feel like it's absolutely worth it, though.
> but I'm concerned about being productive at work.
I'm honestly not sure what to say to that, considering you will be very slow at the beginning. You may be able to keep using QWERTY at work, and practice a new layout in your free time, though.