^ I think that's a great summary of where the state of multiboxing is at the moment.

There's lots of viable options - some slightly better than others depending what you want to do. I don't imagine non-broadcast software solutions like JMB or WOB will be popular in arena, but they're great for leveling and crafting. Any option will probably work for regular dungeons, but there is an edge to hardware broadcasting for TBC-heroics or retail Mythic+.