Personally although the annoying degree of difficult got to me as well, I positively loved the character of Akirakon Sin. If he were canon, his existence would destroy the fundamental morality system of Star Wars. He would be proof that being a Sith or pursuing passion does not make one evil, rather it is betrayal and random cruelty that warped the Sith into something far lesser than they truly are. The way that Silveredge9 created this explanation as to how the Sith got to where they are is perfect because it shows how titles and beliefs do not make one evil but rather what one does in the name of those titles and beliefs.
I do sort of agree with you on Solomon. Granted he is also the opposite of Solomon in that while Akirakon is the good Sith, Solomon is the bad Jedi, so he completes what Silver is trying to show us. However, it sometimes irks me how Solomon get's a "get out of jail free card". Yes he turns away from revenge and gives up his life to save Kobayashi, but somehow I don't think that can atone for what he did. He should get an ignoble death, but he should not die with glory.
But then again, Silver probably didn't see it that way when he wrote the script. It's all how you look at it. Personally, Solomon's Revenge lived up to my expectations. The original BOS got me attached to the awesome character of Akirakon Sin. In that version he wasn't outright evil, he just was opposed to abstractions and actually helped Revan deal with his/her own past. At first in the remade BOS, Akirakon seemed a bit more like an outright bad guy, but then you experience SR and you find out that he's a great tragic hero. If anyone deserves to be the King of the Sith/Dark Lord of the Sith/Sith Emperor, it was this guy.
When it comes down to, I think Silver just made some bad choices in difficulty settings that wound up taking away from Akirakon's awesome character. And wow, I'm repeating myself.