If you do not exceed the resources for a VPS, they are generally more reliable and far more cost effective than a dedicated solution.

I use a VPS for my site. Normally it would be wise of me to switch to a dedicated server, but my host offers some very beefy VPS plans with generous amounts of RAM and very strict burst rates. I havent seen issues with others bursting on the server due to those strict rules.

A good VPS is better than a cheap dedicated server in terms of performance, as its sharing a powerful computer.

Its like sharing a Porche with your friends, or driving your own Toyota Echo around. Which do you prefer?