He's not particularly original, though he is refreshing as a Vulcan who is not tormented with angst from being either half human or deeply flawed. He's an older mainstream Vulcan with hobbies (orchid growing), a family back in the Alpha quadrant he misses, a long term friendship in Janeway and some comfort zone challenges in the form of Neelix. He's one of the least dysfunctional Vulcans we see in Trek and a huge asset to the crew.
What did you see that was "bad"?
Sorry, I'm late coming into this thread, but I would like to agree that Tuvok is a normal Vulcan and refreshingly so. We were chatting in the DS9 forum about Captain Solok and TNG and DS9 saw some seriously off their rocker Vulcans. It's nice to see Tuvok just be a normal Vulcan as opposed to a murderous, rascist, Bendii Syndrome affected Vulcan.