I like his voice. It's fitting for someone who had half of their throat crushed, the gravely tone fits his grave demeanor. It doesn't have that villainous tone because Obito isn't a villain, he's actually more of a tragic anti-hero.
I agree, his young life was so unrealistically painful that when I heard about it, I was shocked to find that there was a villain/anti-hero I really felt bad for! I don't even want to see him punished , I think he's had punishment enough and should get a chance at a normal life, and when his life was fairly normal (despite having no parents and living in the Uchiha police station/prison of Tobirama's era) he still chose to help the elderly.
Naruto and everyone had someone that helped them in time, whereas Obito just had Madara and manipulation.
I liked that Tobi voice in English though, it's really funny and it's hillarious on the Ninja Storm Full Burst 3 game. He has so many daft quotes mid battle like "Awesome, right?" "It's all set!"- with a big thumbs up and "I know you just wanna bully me, man what a jerk!"
The Tobi voice doesn't suit the Obito face though, but I'd love to see the randomness of him talking like that in the midst of the seriousness of the 10tails battle. XD