I went last year and represented AROS. It is an Amiga convention. There are booths of people representing different aspects of Amiga. Of course the sponsors get the centrally located ones but that's to be expected. The people that attend the dinner get to see panel discussions and keynote speakers.
If you're into Amigas of any sort, particularly next-generation OS 4 models, you'll have fun at Amiwest. It's worth the drive and the entrance fee if you're close by.