Let's put it this way. First, EE isn't free. It has licenses; the one we need is more than vBulletin, but barely. It also has fantastic support. Ironically they call it the "PRO Network." I, like you, had never heard of EE before most of this post. So I was a skeptic too. You play this game long enough you know to be cautious.
BUT... I'm pleasantly surprised with something I'd never heard of.
EE can do just about anything you can think up. Seriously, I've yet to find something it can't do. Usually it's my own knowledge that has hindered me. This mainly is bc php can be executed in the EE templates, allowing endless possibilities. EE is different in that it's a lot more than tempaltes, files, and a database. It's about GROUPS of content in a database, templates that run them, and beneath it all files that do the work (that I never have to hack, bc the templates are the workhorse). Plus there are lots of people writing modules, plugins, and extensions for it - all that expand functionality either a little or a lot.
www.Hawaii-Guide.com is running EE and I've spend the last month converting it. PRO will be even more powerful in EE because of what EE can do that phpbb, VB, etc cannot. They are mostly forum based systems. EE is a Content Management System, and is extremely flexible.
So while you may not have heard about them yet... trust me, you will as they grow. A system like this doesn't stay silent for long. The main complaint I hear about EE is that is does MORE than most bloggers need. So that may be why it hasn't grow into popularity in that market. But for sites the size of PRO, it's a perfect fit.
Folks I assure you this project is in good hands. Jason is personally handling the conversion of our data into EE and Jason is the most talented coder I've ever known. On the server side Eric has done a wonderful job of already setting up our new server (I doubt many of you even noticed the switch). I've been doing this stuff for 11 years now, so I have some experience myself.
Trust us... it'll be worth it.
OK, reality check. EE is going to offer us LOTS of things we can't do now. We'll be able to split content up and display it in ways that make our current methods look silly. Plus it'll all be SEO friendly and completely (and easily) search-able. That'll include down to the very comments of various entries (like guides, etc). A lot of our site will no longer be inside a forum environment.
The current forum of EE is about the equivalent of what we have now plus a few perks (like subforums, RSS feeds, etc). Plus, the forum and the rest of the site (news, blogs, guides, etc) will all share a common user base. Overall I'd say the forum move is a lateral move. So why do it?
EE 2.0 is on the horizon and unlike the phpbb guys, they actually meet their milestones. So we should have EE 2.0 by the end of summer or early fall at the latest. That should mean phpbb3 functionality in a much better CMS system.