The lesser of two evils

Hi all

I am thinking of a quick trip to Vegas at the end of May for my Birthday as there are some great fares at the moment....alas not with Virgin (but thats expected on the route).

I am trying to stick with US Airways or Continental, so I can get Virgin miles......anyone have any experience of flying them to the states?

As my last few trips have been in CW and UC and this will be in economy, my view is think the worse and if it's better than that then it's all good.

I have looked at the review sites, but personal opinions welcome.

thanks