OKay so I've now played Battleborn and Overwatch and I have to say, from an Aussie POV it's a no contest win for Overwatch. Why? Because Blizzard really.
I've mentioned a few times that actually being able to try out online only games really matters to me since I live in Australia where the internet is from the 90's, having lived through that once it's annoying to do it again. That said I really do enjoy multiplayer gaming so I'm stuck with picking and choosing my games a lot more than I used to. Add to that games cost 50-100% more in Australia (due to exchange rates and such) and I'm married with two small kids means my gaming dollar means a LOT to me.
So why can I say Battleborn loses? Well I've played both Overwatch and Battleborn for one weekend each when they briefly allowed people in for Beta access. In Overwatch case it was by invite only and I got lucky, and Batlteborn was free on Steam for the beta weekend. This means that the Overwatch beta had the potential for fewer people, or a more targeted player spread than Battleborn depending on how you want to look at that. This matters because Battleborn had a hard time getting me ANY matches to talk about. So lets get right to it shall we?
Battleborn beats Overwatch in that I can play cooperative with humans against AIs. Our team can go in all Dungeon run style in a story based cooperative mode. This is a great way to enjoy all the characters and universe in Battleborn which are rather interesting and crazy looking. The problem here is that it allows up to 5 people to play right? I have had, at most, 4 players match up to play. Most of the time I'm lucky to get 2 other players. No problem right, everyone must be playing the PvP after beating the two story missions right?
Well the fact that I can't seem to find 10 players to play Morning, noon, or night makes it a little hard for me to recommend this game to an Australian audience. No one seems to be playing in this region and because it's a FRIGGIN MATCHMAKER BASED SYSTEM (I can rant on and on about friggin matchmakers) I can't see what region it's matching me to, how many players are searching, or hell what my ping is in game where I do lag when I DO get into a game.
Now Overwatch is on par in the fact that it's a matchmaking system as well, but the population was such that it felt fine as there was enough people waiting to match up that I never had to twiddle my thumbs and worry about a match for more than a minute or two. Plus, they allowed you to tool around shooting each other in Free for all style until a full match was found. In stead of starying at stupid spinning circles with NO information like most bloody matchmakers make me do.
Gameplay wise the controls are tighter and more responsive on Overwatch, but Battleborn had more interesting variety in abilities and characters. I enjoyed getting ISIC as a "Defender" type character because he played way different than others I had used with his shooting/charge mechanics.
In the end, for my money it has to go to Overwatch just because people were actually playing on it in the Australian region. I believe that if I can't find people during a Steam Open beta (where you have arguably the biggest chance to get people's attention) then what chance do I have to find fellow players in my region who have shelled out $100 to play? (Did I mention cost was a factor?)
If money was no object and I was back in the states where I had fiber to the player bases then the choice might be more difficult and tight. IN the end though I think I'd still go for overwatch PERSONALLY because games where I shoot other people competitively tends to stick with me more than co operative gameplay just because AI/Dungeons get boring once I've memorized their layouts.
Your milage may vary but seriously as an Aussie I think you'll be disappointed in Battleborn versus Overwatch even though, honestly they're not the same kind of game.