I use Wave daily with a group of about 18 people, primarily for chat with occasional collaboration. We generate 300-600 messages a day.

I just tried Shareflow and agree that the interface is attractive and the mobile features are a big improvement over Wave’s non-existent mobile capacities.

I found it missing five key features:
1. Ability to reply to replies in a nested way.
2. Ability to specify the order of comments in the flow. Currently, the comment with the newest replies appears at the top, but I’d like to be able to keep the comments in chronological order with the oldest at the top, regardless of where the newest replies are.
3. New message indicator and ability to skip to new posts easily.
4. A way to receive invitations and join flows within Shareflow (without going to your e-mail).

Basically, I think it’s both too linear in the organization of replies and not linear enough in the organization of comments. I don’t need e-mail integration, as my group’s post volume means that we’re on a lot and I wouldn’t want my e-mail clogged with notifications.

It’s a nice-looking tool, though, and with a few more features could be a very viable wave alternative.