I agree with the OP. This "trial" is bullshit across the board.

How it's bullshit as it relates to the story:
A giant winged dragon leisurly strolls across a bridge to nowhere and never directly attacks anything except glowy walls it could fly over anyhow. Meanwhile, it's pooping out additional nasties to deal with the mild threat from adventureres.

How it's bullshit as it relates to advancement:
You cant progress without beating it. You lose access to a roulette without beating it.

How it's bullshit as a trial:
It's nearly impossible to pug. You can't simply wipe to reset - you must wait to suck (you can fail 4 minutes in, but gotta wait 11 to restart).

Other bullshit:
If you are stuck on cannons, you may as well come as a weaver or goldsmith; your fighting skills will go largely unused untill the end. May as well craft till he's in range. I havnt't seen the point to "healing" this yet. We literally completed this with 8 DDs the other day. It's not fun. You cant even LEEEROOOOY it, because there is no threat of wipe.

About the only thing you can say about it is that "it's interesting" or "it's different". I dunno about others here, but If I ate hamburgers every day for a month and saw a pile of rat shit, I wouldn't eat it because its interesting or different.

If this is the direction SE is going w/ 3.0.... *facepalm*