Go for it if you're looking to have fun. Summoner specs are usually a blast to play in games and it's about time demonology was switched over to one. Not how I would have translated that idea into the game, but it gets the job done. But if you're in a position where performance outweighs your enjoyability, you'll probably want to stay as a hunter. At least for now.
Honestly with just a few tweaks to bring up its weaknesses, it could be a solid spec. Something like scrapping current demonic empowerment and buffing pet damage could do a lot. Keep DE as a mini heroism/bloodlust cooldown for pets. Although since it functions like a DoT spec with more DoTs than usual target switching will probably always be an issue. A button to switch all your demon DoTs over to a new target would probably help. Maybe if they just functioned as visual DoTs instead of pets and guardians AI issues wouldn't exist?
Demon Wraths overlapping damage to an extent could help AoE not be so dependent on implosion and wouldn't negatively affect single target damage. Maybe turn it into an 8 second duration with an identical cool down so other spells could be cast during it and it would function like other AoE spells (Rain of Fire, Blizzard, I think barrage functioned like this at one point, etc.). I think a talent or spell to say, make all your imps' fireballs do splash damage or dreadstalkers passively attack up to 2 or 3 additional targets for x% of the damage done to the main target could really help with cleave situations.
Personally I'd like to have a playstyle within the spec that revolved around sacrificing demons to increase your own power, but that's just not the direction they went for and balancing the two options would probably be a nightmare.