I played in the tier 2 in the strategicon epic. It was really well done by the convention; hundreds of players. Lots of fun. I have some quibbles with the design of the adventure, but it was fine.
The thing to realize about epics is that they're a different game than the-adventures-formerly-known-as-expeditions. They're incredibly time-constrained and tend to be 99 - 100% roll play over role play. I don't recommend them for everyone, and I *definitely* recommend signing up for one with a group of friends so you can strategize ahead of time. Signing up solo for them risks being put at a table with others whose playstyle and incentives are much different than yours, leading to a ton of frustration.
Personally, I've decided that the next time the epic is in town, I'll volunteer rather than play because despite the rewards usually being incredible, they're just not my style of D&D.