am working on my first project in xsi, i have switched from being a maya user. i must say that i am happy with the model, animate, render tools. but when it comes to the simulation module i must say it seems way inferior/backwards to the rest of the package. especially coming from a maya background. i really think it vital for this part of the package to come up to standard with the other modules. and the calcutation on the soft body and particle tools seem very slow. phoenix tools are not exactly know for being on the cutting edge of dynamics and you would expect something more from a highend tool.
just seeing what others think
I think that every one agrees that the simulation module is the weakest part of XSI. (but once you get used to it, it's not really that bad) However, with the exception of Hair and a few other cool things here and there, XSI is definitely lacking a little in the dynamics area. I'd suggest that you send your fixes/requests to Support@Softimage.com
This way, as they revamp the dynamics in XSI, they can use your (and other peoples) suggestions to help get it up to speed.
At this point, the rigid body dynamics, and some work on the existing simulations (particles, cloth) is still on the schedule for a subsequent versions. As Ed is suggesting, feedback is very important to us, specially if you give us concrete example of production scenarios and problems that you would like to see solved, rather than just a list of features. This helps us validate and adjust our development process.
This being said, I think that we have managed to make XSI v2.0 a strong contender to Maya v4.0, and the feedback we keep getting from our users is not so much that we match or win the feature list war, but that we make the production process easier and faster.
Right now, in the post-production area in New-York, the XSI companies are grabbing the lion share of the jobs because they can on average turnaround the same or better quality productions in a third of the time.