You should probably quit now since leveling up to vanguard is one monstrous grind, even worse than when you left off.

Just a note:

It now takes radiant fire crystal to heat up your 5* gears, you get about 15 of them on average per T3 clockwork run, and you will be needing 400 of them to reach lvl 10.

a good way to go about it is to only use the 100% option, it costs too much to risk failure

If you go with medium chances, then your expected cost is about 420 Radiants per item. Sometimes it will cost more, and sometimes it will cost less, but that's what it will cost on average. So, rationally, it makes sense to use medium chances, not 100% chances.

(This calculation ignores the chances of forge bonuses such as double level-ups. The effect of fire crystals on those bonuses is not well understood. It's possible that using more Radiants raises those chances.)

Many players ignore this advice, apparently because having to repeat a forging is just too emotionally disappointing.

-Check out the rank mission "A New Threat" as well as Spark and Roar.
-Adventuring is free, but that comes with crown inflation for CE prices.
-The developer team has dwindled. Sadly you don't see them much on the forums or ingame unless you call on them to help with an issue. Probably a privacy policy thing.
-Steady flow of promotional boxes. For the love of Vog don't check the steam comments on those.
-Five new Vanguard missions. They answer some long-standing questions while raising a plethora of new ones.
-Orb barriers for melee combatants. Fire, Ice, Poison, and Shock.
-Turret kits, Recon Ranger summoners, and rocket beacon pickups were added
-Shroud of the Apocrea event, in which three new event weapons were introduced. Shadow/Poison-dealing.
-March of the Tortodrones event, granting a Tortodrone themed handgun and shield.
-Dashing and Shield Bashing

bout all i can think of off the top of my head

Losing 60 fire crystals on a single go would be... frustrating.

One time I lost around 600 fire crystals on a single level. Never do less than 100%. It just isn't worth it.

3 Years? Dang

Ok so basically, OOO made some decisions that ruined some of the magic that the original game had. They introduced missions, which killed the Arcade (of course, someone still does Arcade, probably only Bopp or Fehzor) but for practical purposes, Arcade is useless. You cannot consistently find random parties to join. You pretty much are doing a solo game at this point, and have to make a significant effort to meet people.

No more major updates anymore, only accessories. Though people do still buy them for hundreds of real life $$$ to look pretty and spend all their time standing in front of the AH trying to get a snag to win some of dat sweet virtual currency to get the ladies.... *cough*getalife*cough*

The game used to be a solid 8/10, perhaps a 9. Now that the social aspect is essentially stripped, it is about a 5/10 or so. The story is too disjointed, and the gameplay itself gets old after about a month.

The reason for all this BS? They lost a lot of support for the game, are unable to communicate with players because Sega has them bound, and don't have the resources to improve. Two programmers on a game this huge is pretty much trying to paint a wall with a toothpick. I think they should've spent more time marketing, but at this point everything in retrospect looks good, so no point in speculating! They are doing what they can, which unfortunately isn't much.

TL;DR
You'd be joining a stagnant game. Not dead, just stagnant. You would be using stale fire crystals to upgrade stale armor in order to progress through stale missions. Once you reach the end, then all that is left is to play stale lockdown, or spend that stale energy and buy TF2 stuff or steam games.

What a coincidence. I recently came back after being gone for about three years, too.

There is no gate fee anymore. Even apart from that, getting to five star gear is probably cheaper than it used to be. But heating that five star gear is now brutally expensive, whereas before it was basically free.

There are a variety of new mobs and some new gates. The end portion of compounds is obnoxious, or at least, I haven't yet figured out how to handle it. There are some new missions, too. Missions still aren't interesting, but they give the best loot, so people seem to loop them endlessly rather than playing the more interesting arcade.

It's all bout the gear now I guess

As far as I can tell, since the game started, the only form of character progression that makes you stronger in the game is upgrading the gears.

I came back too, after 3 years. Deciding to have some nostalgia trip through the game. (Though, I'm only rank 5-3 when I left) And started with a new knight. Things changed. And I can't stay still and analyze what has changed or not because I'm just there for the hype. But after a few rounds, there's this one player who dragged me to form a team. After that, when I want to make my own party, there's no party to join to at the arcade. Seems logical, I thought. Since, back then, you automatically join a team with no hesitation. (And three years has passed before that trend.) I guess I'll be rooting for my friend (which the one who dragged me to join his team) to be online tomorrow to have fun for awhile.