Personally I find OP8 is fun, especially at first, and a nice challenge for yourself and your group, but it gets a bit dull in the long run.
If you don’t mind using the most effective guns, gear and skill combinations only and all the time then you’ll be fine, but what OP8 does is kill the variety (when introducing it Gearbox even stated it is a mode that breaks the game and intended as a challenge only), because it leaves no space for experimental builds for fun, or guns and gear that are not as overpowered as the top 2 % or so.
DPUH, Grog Nozzle/Rubi, Blockade, Rough Rider, Bee, Sandhawk, Pimpernel, Florentine, Interfacer/Omen/Twister, Sham and Norfleet are what you will see and use so much that your eyes bleed.
Builds that don’t focus around the overpowered skills like Bloodsplostion, Money Shot, Bore, etc. will not be very viable.
Krieg specific, at OP8 you’ll mostly be using:
Rough Rider (+health needed to mitigate the Silence the Voices damage scaling to lvl 80 and doing insane damage to the players 72 health bar, damage reduction a nice plus too and making it the better choice overall than a +health relic and a roid shield), DPUH, Nozzle/Rubi (to heal above 50 % for healthgating again when needed), Stormfront for building Bloodlust stacks or Magic Missile, Florentine, Carnage/Swordsplosion in a Bloodlust/Mania melee build
Flame of the Firehawk, DPUH, Nozzle/Rubi, Stormfront or Magic Missile Florentine, (see a pattern here? lol) along with the some of the best elemental weapons in the game for a gun focused bloodlust/hellborn build
Pretty much little to no exceptions here.
This is just my (biased) opinion obviously, but after 1000+ hours in this game and a lot of time on OP8 I really like to be able to play around with sub-optimal guns and gear as well just for fun, and there’s no place for that in OP8 as said…
This is what your games will look like: