So how can you tell if you've maxed out express and need to move to the full blown version. Not referring to database size but performance? Asking because we are moving a website and the webhost master asked if he will be on express or full version claiming that express won't be "enough horsepower" Hard to believe that if the database in under 4GB that express can't handle it, I know it only uses 1GB of memory but can you run a report to see if that is actually true?

I think the suggestion was keeping the future in sight. Mainly because of data growth in future which you may not be able to produce now (with less data). Do not forget data size is one of the key factor for calculating performance. Usually expression version is used for testing / learning purpose not for fully grown application and it comes free. And if there is no difference why there would be two different versions express and enterprise.