Well, do you want to stay in SoCal or move to Vegas? Both schools are new, expensive, and have differing accounts of how good the education is. I don't think you could go wrong either way.
I would give UNLV a slight edge, just because it is more established and has a good name in the dental community. Western is more of a wild card. When I was there, however, I really liked it. I picked up the vibe that you are treated as a Doctor from day one, you are upheld to high professional standards (i.e. the dress code/humanistic ideals/cadaver ceremony), and you get early clinical exposure.
The D3 students loved working in the clinics. Right now, since they are building a clientelle, the attending doctors and student doctors are both taking patients. How cool would that be that your teacher just doesn't sit at his desk with a newspaper (every other dental school) waiting for you to ask for help, he's actually taking cases with you and can bounce advice back and fourth.
The D4 year, which currently is planned (D3 is the highest year), plans to be rotations kinda like ASDOH. The sites they were saying you get to go to are really neat. Also, if you have the military scholarship, the student interviewing me said you can go to additional external sites because they have lots of bases and clinics in SoCal. That sounded like a really good experience to me.
In my opinion, rotations are key. You see 10+ patients a day, not 2 like a dental student would. For that reason I think Western would be exciting.