Soul Fire is more efficient at generating Fury than Shadow Bolt, and less efficient Damage per Fury cost in damage than Touch of Chaos. So, while the simcraft profile uses MC procs during Meta, I've not found that to be a DPS increase over saving MC procs for caster form, except during Heroism as a Fury dump, or during the execute where the extra Fury generation from SF is guaranteed.
Soul Fire has a higher burst potential but using it outside of Meta is still the better way to go if you don't have to burst a target in very short time.
The reason for this is that 1. Soul Fire generates more Fury than Shadow Bolt 2. the DPET difference between Soul Fire and Shadow Bolt is usually higher than the difference between Soul Fire in meta and Touch of Chaos (talking relative here) and 3. Soul Fire costs twice the amount of Fury than Touch of Chaos does.