I hardly think you're comparing anything meaningful. The hypothetical PaaS has a certain level of reliability regardless of the client your user choses to use to connect but your user's client doesn't support the server's feature set.
Anyways, I have no respect for anyone using <=IE9. I currently have to support IE8 (and 9 but that's not a big deal) because we deal with Australia and we deal with banks. At this point it's ludicrous that they haven't caught up. IE8 doesn't have the ActiveX lockin that IE6 had and current IE is immeasurably better in all conceivable ways from what's come before.
Anyways, I have no respect for anyone using <=IE9. I currently have to support IE8 (and 9 but that's not a big deal) because we deal with Australia and we deal with banks. At this point it's ludicrous that they haven't caught up. IE8 doesn't have the ActiveX lockin that IE6 had and current IE is immeasurably better in all conceivable ways from what's come before.