Not the same company. URL2PNG takes better screenshots as they didn't just throw up PhantomJS on a server, lift some wording from a competitor, leave the placeholders in a template and call it a day. Missing fonts are the main reason for the worse screenshot quality -- the default fonts that replace them mess up layouts.
as we said in other comment, we have several generators, currently we are using a phantomjs based one, we are investigating more options as we mark this period "Early Access Preview", we are collecting feedback , at the end of it, you will have the best experience ever