The 830 is a super nice machine but the price is just mind-numbing, to me. And goodness - just getting the machine set up to do something is a chore.
You already have an embroidery machine - did it change your life?
The longarm has the potential to save you a lot of time and enable you to finish many more quilts. Maybe even build a small business. Would that change your life?
It would change mine - I would go for the longarm without even giving the 830 a backwards glance. :)