I have no experience with either of the models you mention, but I will suggest that generally, under most "common" live conditions ( bars, taverns, nightclubs, small performance areas, stages) I'm usually not a fan of using condenser mics for vocals.
Because of their heightened sensitivity, and their propensity for picking up more than what you'd want them to, they probably aren't the best choice under those conditions. That's not to say that they can't be used for live scenarios, of course they can, but it depends a lot on the conditions you are in at the time. If you have good PA, and a knowledgeable FOH engineer who knows how to properly ring out a system, including the stage/monitors, then I'm sure it would sound great... but that scenario isn't "common"... ;)

If you do end up going with a condenser, based on my own personal experience with the company and its well-deserved reputation for solid builds and ruggedness, I'd stick with Shure - but that's just me.

d.

I work at the factory so I will refrain from subjective comment as to what is better. You won't find the VX5 noisy in general stage use or project studio applications. The VX5 sensitivity is 5mV / pascal compared to the Beta87a at 2mV/pascal. The Beta also has a self noise of 23.5dB neither will be a problem in normal use. The VX5 is a very well behaved stage condenser and may surprise you where it can work. The guitar / vocalist in my bar band uses it on the same stage with my Audix OM5 dynamic and very rarely does he swap it out for a dynamic. As Donny mentions we do know what we are doing and it is not common. But it can be done.