Same here , me and a couple of kinnies just finished some testing on instances on beta build 4.
We rolled with holy trinity build on 3 mans ( guard , minstrel , hunter ). We used t3 gear , t3 relics and maxed LIs.
As vastin mentioned in the past , t3 gear and relics won't be available on live , our actual live gear will be less powerful. ( keep that in mind for later )
First of all , there are some visual bugs on quite a few instances. Ruined city is almost impossible to navigate , there are missing floors , walls etc.
Quays of harlong ships are replaced by a few osgiliath orc raft-boats xD
I am sure there are others too.
Regarding difficulty.
Long story short : Everything considered scaled instance on live at the moment is alright.
Most fights will take longer , but it is certainly a step towards the right direction , some scaled instance mechanics come back into play and so far so good.
However , pellenor instances scaled to 115 are a total different story. The troll fight in Harlond is extremely hard to complete on t2.
And yes , we did avoid khurat's rock throw and interrupted kalmok and all that and we also tried multiple times.
My overcapped mits minny ( 60k+ morale ) got one shotted by akhun's charge attack.
Once , after me and the hunter died , khurat threw a rock on our 100k+ 5-stack fortified and overcapped mits guard, and he got hit for 80k.
Maybe it's doable with lm's CC and debuffs and a lot of luck but still , it's quite broken atm...............
And yeah , you can forget about aoe zerging the trolls , Khurat has 1.6m morale and the other 3 1.3 , while dps is pretty much the same or worse comparing on live ( depends on the class ).
I am guessing similar problems will appear on black serpent last boss and gloom of nurn on SS t2.
Also , i am pretty sure lumithil on RC t2 will sometimes one-shot every non-tank class.
Lastly , throne doesn't seem to be scalable anymore.
I was really sceptical about posting this info , because there is a good chance the fix will be 'nerf everything to the ground' instead of tweaking each instance separately ,
and that would be a huge shame , considering how many instances actually feel better now.
The problem is simple really , some instances on live have difficulty of 1 while others have difficulty of 10 , but they all got the exact same overall difficulty increase.
Imo , the best fix for this would be tweaking the t2 buffs. Like increase mit penetration , reduce extra damage a bit or whatever the devs see fit.