My thoughts on the lab.

I love the lab in some ways and absolutely hate it in others.

The puzzles are interesting.. once.. but puzzles aren't really ARPG content as far as I'm concerned and are thereafter annoying. I play puzzle games when I want to solve puzzles, and I tend to play them once.

The three trials with random (non-trap) supports makes for an interesting new boss fight. The varied layouts and optional keys for added risk/reward and time investment are great.

Having to stay alive for the trial is also great.. thematically. I don't think it gives the rush of hardcore to standard players though so much as the frustration that standard players intentionally avoid by playing in standard. Nerf frustration (trap gauntlets) and buff adrenaline rush (dense/interesting mobs).

Traps in the doors that sometimes catch me off guard (usually blind-ish navigation by map) are pretty cool and the breakable walls are a neat addition. I don't even mind the occasional floor-moving trap of any variety.

But I absolutely hate running trap gauntlets. And that includes fighting Izaro with a floor full of them. The molten floor is also not fun, however easy it may be once it's figured out and/or bypassed (in many places) with something like lightning warp. If traps were a complement to the mobs, they'd be amazing additions to the game. Sparse molten patches in a room of mobs, rather than a molten gauntlet with a few mobs to get in the way, would be fun. I want some dressing with my salad, not some salad with my dressing.

Having to play through the game three times on a single character is annoying enough. But now the once optional zones are mandatory to unlock the lab and ascend. This made the path to maps longer without really adding new content. I like how the extra zones have been made more important (and I often run them eventually anyway) but this only increases my desire for a single playthrough as you've effectively added several zones to the shortest relevant path.

I find the ultimate objective (random enchant) for repeat runs quite underwhelming. It has the potential for an amazing result, but by far the most common result is undesired and completely irrelevant. I don't know how many potential results there are (I presume hundreds) but when the expected return from a lab run is disappointment, what's the point? Are repeat runs worth not running a map instead? Bad idea, enchants (implemented this way), I think.

I've long since switched from hardcore when I play (for short bursts) for various reasons, including my own love of glass cannons, lack of focus at the wrong times, and general incompetence. The lab is just another reason for me to stay out of hardcore.

The lab seems to make even the tankiest build a glass cannon, but not in an enjoyable way.

Even if just the trap gauntlets were removed in favour of sparse but cleverly located traps I'd consider it a decentish addition to the game, if not a repeatable one. There is/was a lot of potential in the lab for awesome, I just don't think it's there (yet?).

I hope the lab and I improve significantly in the near future, because PoE just became less enjoyable to me.