That you thought would be amazing, and it wasn't? I had a blast leveling my wiz. Hit 70, managed to get a full firebird set to run a firey disintegration build. All ancient gear, gemmed up. I'm sitting at 683k dps, 9760k armor, and 1301k health/life Gen and such. Overall he's my highest geared class.
Now I've been working on barb and necro, and I have unlocked up to gr44, figured I would pop my wiz into there and break him in... He broke alright. Got through the first two floors fine. Hit the third floor wich took me to the woodlands of arreat... The mob density sky rocketed and there was no open spaces to recoup. There was no white snow either, just a sea of red health bars and moving mobs. I died about 10 times before my gear broke completely and I had to leave.
Anyone else gear out a class they liked only to find themselves dead in certain situations?
It happens a lot. But it's not a matter of the class, it's a matter of the build you've chosen. You might just be playing a certain combinations of skills and items that either doesn't suite your playstyle, or that you need more experience with.
Here are two examples from my experience:
I loved the monk a few seasons ago and played it a lot. I loved the old Sunwuko set. But ever since it got reworked and is now heavily dependent on Sweeping Wind it just doesn't work for me. Just not my cup of tea. Which sucks, because it's by far the best set/build. So yeah, I only play the monk as support on season, and on non-season luckily I have godlike LoN gear so I don't have to use the SWK set.
Another example is the Manald Heal wizard. I have a lot of friends who are generally really good players, top 10 potential if it wasn't all just a paragon/bot festival (and who held top 10 spots before paragon/augments was the meta). And they're quick learners. But every single one of them struggled to get into the Manald Heal wizard. It just takes a few runs, and sometimes even a few days, of really feeling the true power. Once you do the MH wizard is the most powerful thing in the game currently when it comes to any speed farming activity - by a margin. But it's not for everyone, and it's not something that works just by copy/pasting the build. You need to give it some time.
Generally as a piece of advice, if something doesn't work don't bash your head against the wall in a GR that is too high. Go in a Torment rift and an appropriately low difficulty and just familiarize properly with the build. Learn each and every skill, figure out if there is a rotation and what can be maximized, and only go higher once you're really melting through stuff. A lot of people think "oh I beat this rift in 14:30 so I'm definitely too good for this, let's go higher". Yeah... not really - unless the build relies on having lots of mobs around and is supposed to be slow, going higher is never better.
I definitely think that the issues are a bit of everything. Not quite used to the new playstyle, my gear may be a bit off, just a general combination of everything. But after getting so wrecked, it made me wonder how many other people it has happened to as well lol
all ancient gear, and 683k dps, there is definitely something wrong there. either your statement or your rerolls on the gear. also you have to learn the build, firebird isnt exactly the most straightforward set to play, especially if you dont go the archon/chantodo route.