Which application server for Solaris?

We are running Solaris 2.8 (initially on Sun 450s) and considering WebLogic Server, WebSphere, and iPlanet. We had originally selected WebSphere, but we have found that it may not be a good match with Solaris. WebLogic is the market leader, while iPlanet is a conglomeration of Netscape, Kiva, etc. that we are still skeptical about.

If you have any experiences with these 3 application servers on Solaris, we would appreciate your opinions: How do they install? How easy/difficult is configuration and tuning? Is the app server stable on Solaris? How’s the throughput and performance?

We are reevaluating these products, and I will be happy to post what we discover, within a month.

Thanks in advance.