How large is Act V compared to previous acts?

How much content is there in Act V in Diablo 3: Reaper of Souls relative to other acts? For example, Act IV is generally considered to be around half as long as Acts I-III.

Qualifications: Assume that I am playing on an appropriately-challenging difficulty level (i.e. not cruising through on Normal with a pimped-out character), not attempting any speedrun shenanigans, and am experiencing the content for the first time.

(I'm aware that the RoS expansion adds plenty of additional content in addition to a new act, but I'm just asking about the additions to campaign mode.)

Solution 1:

Lengthwise I would say its about the same as act II or III. It took us 8 hours to clear it from level 60 in tourment 3 but we did not explore 100% and there was a lot of discovery. Once You'll get used to it and the new map I think it's fairly equal to II or III . The first act is a bit faster in my opinion and act IV is obviously way shorter.