Man fuck the spoiler tags, the whole thread has spoiler in the title.
But anyway, I actually really liked the episode. If nothing else, it contrasts against regular television which has predictable outcomes fitting into the nature of both status quo(preventing the show's formula from changing if it's considered "working") and upsetting the regular viewers. For example, in an episode of the Simpsons, Homer can't cheat on Marge, even if it's something that might actually happen in real life, because then then people might stop watching the show.
The suicide came sudden and without warning. While it's true that suicides often have clear cut warning signs, it's not always the case. Kutner himself would know what those warning signs would be, and if he truly didn't want to ask for help, he could disguise them. I like it because it felt like a real life event to me, not foreshadowed, not hinted at and not making sense completely. The only reasonable explanation being that Kutner was extremely adept at hiding his depression.
I had thought there was a lot under the character's surface not being shown, because he was clearly the only one on the show who was nearly equal to house in terms of intelligence, as was demonstrated by his deductive skills, yet the only personally he showed outward was lighthearted and shallow(I don't mean as a negative connotation). To me that showed something was off with the character(though I didn't see suicide coming), or perhaps it was just the actor's personality coming through.
I am sad to see him go as he was a great character and I like the actor. Though I must admit it's rare for me to be surprised by something on television. Wounded and nearly dying, some strange disease, a long drawn-out death even, sure. Don't think I've ever seen a main character just stumbled upon dead before.
I also think it's pretty obvious there was no murder and it was House just trying to make sense out of the senseless. I don't think he's been as shaken ever in the series - and I think it's going to have long term negative effects on the character. Most likely a depression.