So I've been in the beta for a while now but only recently am getting really excited to play the final game now that it's so close to release, so I haven't been up on all the official news, so I apologize if this is all common knowledge. I know that based on the player profile there are 4 acts, also from what I've read the level cap is 60 and there are 4 difficulties that I assume work like Diablo 2. My question is has it been officially stated how long the acts are compared to the beta or Diablo 2, and what level you would be around when you finish normal? I know the beta most likely has a sped up leveling curve in order to test out more abilities, but I think it's going to be strange with the way things unlock based on level if you beat normal and are only level 20 and haven't unlocked most of your abilities. I only played normal Diablo 2 (pre-expansion, never went back) and finished around level 33 if I recall. I just don't know yet if replaying on a higher difficulty is something i'll be interested in doing, though the gameplay systems look accessible but still challenging enough that I might be down with it depending on the game length.
Well I am by no means an expert on PvM content. However ill try:
At end of normal I believe you will have already unlocked all of your skills for use, but no runes?
At end of hell you will be around 55+, with some grinding you will hit 60.
As far as length goes, I believe they said the last act will be the shortest as it feels like you are near the end like D2 did with Act 4 and they liked that, they said it was similar in length to D2.
The combat this time around I feel is much more rewarding, you bought the game for $60 may as well see it through to at least try inferno.
It all depend on your playstyle. If you take D2 for example, if your a top player that knows the game, farming spots and so on, you could pass through normal in 10 hours easy but if you like to explore, do every dungeon etc it can take up to 50 hours.
It is all individual, i myself like exploring, i did normal d2 run in 11-12 hours just to see how fast i can do it, but my normal playthrough is usually about 50-60 hours because i like to repeat the act bosses a few times and explore the map.
Besides that, you can run normal or ngitmare as many times as you want, the replay value of diablo is it's best part!
Conclusion : You can't say a set of hours because it depends on so many factors, it is a lot, trust me!
For your question about levels, i also think it is relative. If you are someone who have played diablo 2 for 10 years you could get to hell for example on lvl 52 or so and play. But if you are not you will farm some normal or nightmare to make things easier for you.
My friend got through normal LOD on lvl 29 once, while i usually end it on 35-36. Depends on the playstyle