I'm really excited about Reflex.
In my mind, the death of the deathmatch arena genre was precipitated by Quake 3 and finalized by Quake Live; Q3 purported to be the most balanced deathmatch game ever made but it rewarded aim over tactical play by default and created a set of weapons that as a whole were not particularly satisfying to use (except for the 100 dmg rail, of course). The poor weapon balance, specifically the weak ass rocket launcher, combined with the tickdown spawn health completely killed any chance of your average newbie having fun in the game.
Q3, despite the fact that there was a pretty solid OSP TDM pickup scene for awhile there, also killed arena TDM with a combination of the fucking STUPID machinegun, moronic armor stacking system, and weapon balance. Again, a result of rewarding aim over tactical play combined with a relatively level weapon balance spread offering much less incentive for positional play (too easy for people to swarm a position with machineguns and other, traditionally low-value, weapons).
id software made a huge mistake by building quake live on the presumption that quake 3 was the best deathmatch game ever made, not even bothering to consider changing gears and pushing the genre in a new direction, or learning from their previous mistakes.
A lot of people assume that the arena FPS genre is dead and point to all of the examples of shitty failed games that have come out since Q3... here's the thing though, literally every deathmatch game that has come out since Quake 3 that claimed to be the successor to arena FPS games of the past have been deeply flawed in one way or another: Quake 4 was literally Quake 3 on a shittier engine for a long ass time; Painkiller had absolutely worthless netcode and kinda dumb movement; Xonotic runs, looks, plays like shit; Warsow had a dumb dual-ammo system for years and the game is still too focused on movement; UT3 wasn't even a complete game until they released that massive Black patch a year or two after the initial release (and it always ran like shit); Tribes: Ascend started out decent but quickly became a joke when the developer realized they didn't have a Big Ass F2P Hit on their hands; etc etc etc.
The recent alternatives, like Reborn, sound super gimmicky thus far, and move away from the ideal arena deathmatch game being something that focuses on easy to grasp but difficult to master mechanics. I was hype for it but the more I hear about it the more I'm changing my attitude to one of caution, because I've been burnt by a lot of boring stupid games over the years.
If Reflex gets it right, it has a serious chance to be played for a long time. At the very least, it'll be a retail product somewhat similar to CPM that you'll probably be able to buy and patch via Steam, which'll guarantee the barrier to entry will be much lower than an old ass Quake 3 mod, and hopefully that'll help create a quality community. It might resurrect the arena deathmatch genre. I really hope it doesn't suck.