> have to do a network request for each and every validation of user input. HTML5 solved that to a first approximation client-side. Often later you'll need to

> have to do a network request for each and every validation of user input. HTML5 solved that to a first approximation client-side. Often later you'll need to reconcile with the database and security, so that will necessarily happen there. I don't see that being a big trade-off today.