I will preface by saying that I have played this since beta and I am a huge fan of Tribes. And just because I want to have more people to shoot at, I'm going to recommend this game. I will go into flaws though and what some players who haven't tried this yet may want to keep in mind.
Tribes Ascend is a weird tiny beasty... It is a solid game overall, but frankly, HiRez dropped the ball pretty badly. They stopped development on this game completely. They did this in order to pour all resources on Smite, and despite doing something so "♥♥♥♥ty" to a rather unique game that only needed a tiny bit of love they also ignored the cries to let the community mod the game. So this means that the main reason the older Tribes games are still around is totally non-existant here. There are no new maps, no new waepons and definitely no new updates coming.
What this means for new players is that they are pretty much getting a "complete" game, whether the game itself is complete or not. This is not too bad, to be honest. I can't quite say that it is balanced, when it comes to weapons, and you will most certainly get wrecked by players who played this game longer but I think that is the charm. There are no totally overpowered weapons (even though the sniper rifles and some other weapons can get really annoying) and this is mostly down to how the weapons work. It takes time to get good enough with a weapon to even hit players. It takes even longer to get a Blueplate with a spinfusor (hitting a person in the air with a spinfusor weapon) or just hitting people with the automatic rifles. For me that's what the charm of the game is, there's a lot to do with how good you are at it.
Another thing to note is that this game is all about teamwork, you need people to defend your base, some to attack and disrupt the enemy defence, cappers to get the flag and chasers to chase the enemy flag carrier. Ofcourse, this is the optimal setup and doesn't always come into play on pub servers, but sometimes it does. And this is another charm of the game itself, if you are bad at shooting at people, then maybe try your hand at capping the flag. Or if you can't ski that great, can try vehicles or being a juggernaught bombaring the enemy base from far away.
All that is all good and well, but the fact that the game is "dead" for the developer is a huge blow. And while I would recommend this to any player who wants a fast, skill-based shooter, I would also say that you might get pretty bored because there's no chance of anything new added or any of the totally crappy maps being changed for the better.