It really depends on what you are using it for. If it is just the occasional purchase to withdraw then volume doesn't really matter. If you are an active day or swing trader then you will be at a big disadvantage using an exchange with low liquidity.

The big difference between now and when Mt. Gox happened is that there are many more large exchanges so even if one was faking numbers it wouldn't have the same effect on the whole market. Back then Mt. Gox was the market.