The mobile version of Tasks is all of those, except the offline bit of course, but it's intended to be used on mobile devices with internet connections. Seems to load up quickly and be very fast to use.
I'm already using Things on my Mac and iPhone, which being a native app is faster still, and also syncs between devices. But for on the road capturing of data and ideas I'm still a proponent of paper and pencil:
I think it's a question of left brain vs right brain. Today my notepad & pencil were perfect to help troubleshoot a local area network - a quick sketch of the connections, jot down login credentials, add a few next actions. When I'm out and about and an idea comes to mind I capture it with things. I think I'll always use both depending on the situation.
Congrats to the labs team, Tasks mobile looks great.