Just tried +1x8 on my SR/DM tank, some thoughts:
Definitely a challenge. The groups can kill me if I just stand in one place and they surround me and then multi tar patch me while I cant jump or move out of it. I was kind of surprised that they were really that much of a threat even with all the tar patches because I was still sitting at close to incarnate softcap, but then I remembered SRs -def debuff resistance for some reason scales with level, so I was only at like 65% because I was auto exemped down to 29, and this is low enough for my def to actually get debuffed.
The other pain point for my build was not having FA, and hence not having any -tohit debuff resistance. Soul drain right off the bat to counteract the -tohit of the autohit nightfall helps, I could kill things decently, although I still hate whiffing. In the same vein as the defense issue, I think this is mostly because of the level restriction. Debuffs can be very debilitating when we don't yet have all our fun tools to deal with them.
All in all was a nice change of pace, I actually had to move a bit, like @Werner said it felt sort of similar to the 801 series,