After several runs with PUGs, I have to say that the difficulty level of the two dungeons, namely White Gold Tower and IC Sewers is not in line with all other 'normal' dungeons. I've been testing with several groups, whose setup was like: 1 player level 15, 1 player level 20, 1 level 30 and a VR 16.
This point of view is from a max level healer perspective Templar & DK (bubble/spot heal spec).
I've already stated that the IC-dungeons are not random-friendly and I, therefore, wish that White Gold Tower and IC-sewers are removed from the group finder list and put in a "special compartment", which is not together with all other 'normal' dungeons, which are exceptionally easier than those 2 dungeons!
I beg ZOS to check their 'data' and to analyze the stats about these two dungeons: How often are they picked up in the dungeon finder? How many groups do actually succeed? Etc...
I KNOW, dear reader, this game is too easy for you but it might not be for many of zs. A 'normal' dungeon, nonetheless, is expected to be a more-or-less "easy run" and to be in line in terms of difficulty level with all the other dungeons. As a great supporter of random players, casuals and all others that want to enjoy the "new group finder", I made up my own opinion, which is not so positive.
If you want "difficulty", go for veteran dungeons. This game has to offer dungeon content, which is easy to digest and WTG and IC sewers are definetely not "easy play", please make this dungeons easier OR remove them from the random dungeon group finder!