Since it ended up as a blog-kind of topic anyway, I guess I can share the final entry.
I wasn’t satisfied with me kinda sliding through Shattered Realm, but at the same time, I had a hard time selecting a “satisfying” level to end on since it’s, well, infinite.
I finally settled on 80, as this is the level which unlocks the final waystone, so it kinda marks the end of the content.
This is by no means an achievement, since people went way above 100. I am very sure however I could do way above 100 with my main character as well, since 60-80 was easy and I just went through it like a hot knife through butter. Maybe one day… the problem is, that infinite dungeons are just… meh for me. I’m not exactly a fan of things you can’t beat, or complete… it lacks that satisfaction of completion. You have to decide yourself that reaching level XYZ satisfies you. Oh well.
Side notes:
- Why on earth does the portal open up far away from my char at times? it’s just 20-30 seconds of pointless walking through an empty SR level. Huh.
- I also don’t get why, after you beat the last guardian, the music doesn’t change. Keeps going. Where’s the triumphant ender? I killed the guardians already!
- Why is there no Steam Achievement for SR higher than… umm… 25 I think? The quests end up at 50. The SR armor unlocks fully at 60. The final waystone unlocks at 80. Any of those would make a fine achievement. @Zantai any explanation?
Even more side notes: I retired my #2 (Wildblood Ritualist) after the nerfs and will probably check how my buffed Warder fairs against SR now. Still don’t have a clue what else can he do against Rashalga spawn at high SR except fighting her after eating Aether Cluster for 10 seconds, then running in circles when it is on CD. Rashalga’s “shotgun” does around 500k damage on SR65 already if you eat all of it. Lol. He’s pretty much purely a left-click kind of character focused on physical damage. Yeah, same guy that I used for killing Crate of Entertainment for the first time… Back when it was quite an achievement, haha. With only a couple lame youtube videos about it 
Either way - now I’m fully satisfied with my completion, since I unlocked the final piece of content I guess I can say GD is now REALLY completed, haha.