While I can't comment on the BSS, I can however on the Q-SYS.
We have a CORE 500i (it's just bigger) and multiple I/O frames in a 18k+ seat arena.
There is absolutely nothing that I have thrown at it that it can't do.
The GUI can't be any easier to create. Custom control pages (for your iPad) are amazingly simple. Automixing works very well and is easy to setup and operate.
by the time you add in the audio players, LUA scripting, ability to mointor audio remotely and all the other features, Q-SYS is the only DSP I will ever request anymore. (budget permitting of course)
While I have not used an ipad to control it yet, using a windows tablet works extremely well.
Give the Op only the controls you want them to have and be done with it.