I played in the open beta.
It's a control point capture game where they throw in extra missions. So while you're fighting over control points, they might throw a mission at you like escort the vehicle, escort the general, capture the intel, and so on. Completing these gives you bonuses, such as the use of the vehicle that you just finished escorting, as well as more points.
Combat isn't the straight-forward linear gameplay you get in most shooters (I never played Tribes 2, so I can't really say as to that). The jetpack is mainly for clearing large obstacles, getting a height advantage, skipping elevators, and last minute escapes. You have armor and shields, and each of the weapons have different penetration types. So the assault rifle has mid-to-long range punch, but mainly hits on shields until they go down. But close range, some of that hitting power might hit straight onto the armor. The SMGs are deadly at close range, since they mostly ignore shields. Sniper rifles, rocket launchers, they're all good at different things.
Your loadouts can make a difference as well. You can take a repair tool and extra grenades, or you can grab a stealth device that blocks radar from picking you or anyone close to you up. There's enough for varying playstyles here, especially if you're coordinating loadouts with your team.
You can also choose powerups (essentially, anyway). You have a limited number of these (I think 10). They can be put into a number of categories, such as armor, shielding, repair, jetpack/sprint recharge, stealth, and so on. So for a close range fighter, you can load out on armor plating. Long range, shields, sprint, and stealth for sniping.
Instead of a normal respawn, you're immediately taken up to a dropship where you airdrop in. Certain areas are covered with anti-air, which can and will shoot you down. Drop in, hit the airbrakes so you don't hit too hard and take a few seconds to recover, and you're off and running. This allows you to jump in on that camping jerk who just sniped you if you know where he is or if he shows on radar. The same can happen to you. But still, the first time you get a kill by pancaking someone from 10,000 ft is totally awesome. 
As for getting around: if you sprint for a few seconds, you go into hyper-speed. Steering isn't as sensitive, but you can cross most of the map before the bar runs out. If someone's health is low, you can also kill them by running into them (although I never managed this). So you can get most places quickly. There are also vehicles that you can get by earning enough points. Small battle-mechs that stomp around with gatling guns and can make short 10 ft lunges are available, as well as tanks. 
Other things can be called in, such as supply depots, or mini-anti-air turrets. These can be used to help defend points. All in all, they give you enough leeway for a bit of strategy.
I quite enjoyed it, as it's not very similar to some of the other shooters I tend to play. Good mobility, satisfying weapons (for the most part), jetpacks (yay), tanks, mecha. At the time I was playing, I thought it was fun, but didn't think it had a huge amount of lasting power. I could have been wrong, but I haven't played since release. It apparently now has voice chat, or so I've heard, which is definitely a plus. If I recall correctly, it uses Games for Windows Live, and has had some technical issues.
If you're lone-wolfing it, it's going to be a bit harder to win. But if you get a team coordinating, it can be a blast.