I fought one like 10 levels ago. He was frankly underwhelming 
I'm glad they didn't repeat the nightmare of level-scaling in vanilla Oblivion, and the slight tip of the hat to an Oscuro's Oblivion Overhaul mod style of "leveling" is nice. But I think they should've taken it farther. Whether by new mobs, larger numbers of them, speed and/or accuracy modifiers (NO DAMAGE MODIFIERS!) or "ambush" algorithms, the game should be incredibly white knuckle as you get into the higher levels, instead of what it is: you get past about level 50 and you are effectively invulnerable.
A level or two ago I was exploring over toward the coast north of the city. Mainly looking for ingredients but also on my way to rescue Lucy Abernathy for the umpteenth time . . . My wife was in the room and we were talking and the puppy was playing, so there was some distraction. I suddenly came on a little swarm of bugs, couple black bloat flies, one or two blood bugs, and started backpedaling and whipping out the shotgun. Then I hear this robotic female voice and start taking major damage. I popped a drug or two, and THEN I hear a Mr. Gutsy.
So there I am talking to my wife, trying to ignore the hyper puppy, and fighting five or six mobs (all this is on Normal mind you, I just do not do "bullet sponge" dynamics). Turns out the robots were a "Colonel Gutsy" and an "Assaultron Dominatrix" or somesuch. She had stealth and some kind of gigantic laser beam.
I was wearing ballistic weave Mk 5 courser armor and an amored fedora, and my two primary weapons for such a situation are an incendiary shotgun modded for rapid close quarters fire and a plasma-infused .45 also modded for CQB but at "intermediate" range (all semi-auto, have no commando ranks yet).
Long story short, I nearly died, as close as I can recall coming in like 20 levels. After dispatching the bugs and the gutsy the dominatrix was still pounding me and I was dodging and running (not optimally given I was in a ravine and there were trees and bushes and slopes). I noticed I was at like 15% health and hit my stimpack hotkey a couple times and kept back pedaling.
Dogmeat kept me on target with the Dominatrix thing and I took her out pretty quick after that.
Ideally, I should be having white knuckle engagements like this every other time, but as it is, they only occur very rarely. Once every 8 or 9 engagements if that often.
I will mod it to achieve the desired outcome myself once GECK is out, but it is my one major criticism of the vanilla game at this point: the game gets too easy at high levels. Obviously the bullet sponge and excessive bullet sponge settings might be a bit different . . . maybe it doesn't get easy until level 60 or 65? But like I said, not playing that gimmick.
Mobs that get faster, more accurate, more stealthy, more attentive, more of them? Yes, gimme! Mobs that just simply absorb more bullets? No. You can keep it.
@ OP: you really should go check out the Glowing Sea, yo! It is pretty RAD
. . . no seriously it is really ATMOSPHERIC. One of the better done landscapes and quite engaging in how different it is from the rest of the map.
A new lands mod that expanded the whole Glowing Sea would be a hot potato. It would download like hot cakes. There would be smoke coming out of the power lines from all the electrons flying . . . Sorry I'll show myself out now . . .