I've run thru about 6 or so. My impressions? A lot of stress involved. Seems the usual thing is to run thru them as fast as possible hacking away...I'd guess to get the best drops.
I usually do regular delves alone...using invsibility potions and sneaking a lot. I take my time and collect stuff along the way...looking for chests and the few higher level crafting reciipes that can be found...plus the SHARDS.
My characters are not total wimps..they can't be when delving alone....and I'm probably doing my share DPS wise. But I only follow the front runners since I'm not sure as to which way to go.
Drops I'm getting are not that impressive...I can find better stuff in regular chests and thieves guild drops out in the back country....plus a boatload of materials, etc.
So when do I get to the good stuff that would pay for all the trouble?
I know nutting....