My friends and I had a bad experience at Vegas a couple years ago and would probably not go back. We felt the overall crowd at the convention was all so much younger than we were used to...and immature at that. My friends got kissed and licked on the face by random people! The costumes in the halls did not make me feel like wearing mine. Also I felt guests/programming was really geared towards voice actors and at one point, the only thing to do there was to do was get autographs. (a shame if you aren't into English VAs at all like myself)
Tenshi did do a great job with the cosplay masquerade, though. It was not stressful to enter or be judged. I felt the quality of the skits was overall lacking, again that probably relates to my earlier statement! Hopefully the con overall has improved. ^^ It's also a great place to do photoshoots outside of the con, especially if want to ride the monorail down to the strip!
I believe Animeland Makiba is another new convention in Vegas.