[Seaside] Multi-page updates : Comet? Asteroid? Others?

[itsme213]

If I have a user with multiple pages open on some shared objects (or 
multiple users needing to see each others' updates), and I want to keep 
those pages updated on shared object changes:

- Is Comet the best choice? other options?
- Is Asteroid the starting point? other options?
- Is it very complex to use?
- Is it integrated with Seaside+SU? If not, how hard might that integration 
be?

If I can limit to single-user/multi-page, am I better off building a richer 
single page (panels, tabs etc.), rather than trying to manage multiple pages 
that need to be sync'ed?

Many Thanks - Sophie