Tera has really fun combat, I love BAM, its colorful and has a unique feel with its races which by the way fantastic it has no factions..... buuuut
Trinity system in place with all its terrible flaws, its argueably a step back from WoW which at least has specs, mystics always heal, lancers always tank, no inbetween or variety in what you do or how you do it. Every group still needs utility which few people want to do, you still get stuck waiting around for a healer or tank and can't really progress in group content without them.
Grind grind grind, the quests are some of the most generic quests I've seen in a loooong time. Kill 10 boars, collect 10 boar hides, go talk to Bob at next quest hub, he will tell you to kill 10 raging boars.
Story is meh in my opinion. Distant threat of the argons coupled with rampaging beast people and the like. Just keep clicking "For the Federation!" I don't really feel immersed. I am just going through the motions swatting at monsters that will respawn 15 seconds later.
A lot of the abilities seem poorly thought out on my mystic, why do I have 2 melee ranged AOEs on a ranged support class? Thrall of vengence and thrall of protection feel really weak. Ring of Corruption seems poorly implemented. These spells make me feel as if the developers haven't been playing my class. I just feel like simple changes could have been made to make them more suitable.
The art direction seems to have multiple personality order which tough mean looking Aman standing next to cartoonish popori or the odd Elin with the bodies of a 12 year old girls coupled with a furry fetish or the pegussus transport that looks like something straight out of my little pony. Not really one to rag on art or graphics but these things tend to be difficult for me to take seriously and I know the western market generally agrees with that sentiment.
Gear in pvp: there are stats and level differences that will unbalance pvp, this will leave a sour taste in the mouths of people who prefer fair or even grounded fights.
Speaking of pvp the "I'm too high you can't hit me!" limit is just a tad too small in this game, its like 2 or 3 levels and you become god over someone.
GW2: what I have on it-Interesting established lore, personalized storylines, open world exploration leveling as opposed to set path quest grinds. Content remains challenging even as you level. No trinity dependence so I can play what I want when I want, subscription free. Dynamic world that changes according to succeeding or failing a mission. PvP is equalized regarding gear, people can't just beat me down because they have 20% more resilience on their armor or something. Classes can use different weapons and specs and play different ways.
Particle effects are out of control. Water combat is disorienting and looks like a failed experiment. As far as I know no open world pvp outside of the WvWvW or battlegrounds.
I can't really account for GW2's controls or spells or grouping because I haven't tried that, but so far I will say GW2's story and questing looks like it trumps Teras. PVP of both have their odds and ends. Raiding obviously goes to Tera I think, but exploration is Guild war 2's. I find leveling in Tera to be very grindy and unfun, it reminds me of what I've been doing in WoW and its lesser reincarnations over the years, and it will certainly make getting to 60 feel like a chore but then I am a mystic so this is especially true to me.
I'm glad people like the combat so much but there are some deep rooted flaws to be found in other areas.