I know I'm probably going to catch a lot of flak for this, but I actually prefer this current Horatio than from the earlier seasons.
Yeah, Super H is sometimes hilariously ridiculous. Yeah, he probably should have been injured his fair share of times - and probably moreso. Yeah, he's practically a vigilante. But all this, for me, makes him such a more interesting character than the lieutenant detective from the first few seasons (at least 1 and 2). Back then, he was just like any other cop from any other cop show.
Okay, sure, I miss H being part of the team, etc. But look at how much shit is on his plate now, post-Speed. I like that he can look out for all of them once in a while, but other times just step back and say, "You guys take care of yourselves (or, take care of each other) -- because I have to take care of myself, too."
I, for one, am thrilled the writers have the guts to give him such a dark edge. We have ENOUGH characters who are all "JUSTICE JUSTICE JUSTICE!" How about some vengeance? To have H walk the line between justice vs. vengeance, police officer vs. vigilante is very daring and extremely tricky to write. Sure, it fails at times. I'm the first to pick apart all the episodes and admit that. But I don't see any other character in the CSI franchise who even comes CLOSE to H in terms of depth, angst (this word is thrown around and misused too often; look it up, please), and (moral) ambiguity. The best way for me to say it is that Horatio is very human in a very larger-than-life, comic-book way, which is fine by me. He's a pre-apocalyptic (or even just apocalyptic) hero, and if you view his character in this sense, I think you can begin to see where the writers are really coming from. The new question the writers are posing is: What kind of world do we live in if our hero is himself beginning to fall apart in the darkness? In the other CSIs, you don't question who the heroes are; there is little doubt in any viewer's mind. For Miami, we do... We question Horatio's judgment and control, and the show is all the better for it.