I'm still using the 9700, if I were to upgrade it would b to the 9790. Pretty much the same form factor as the phone u have now, excellent vattery lifr plus OS7 and touchscreen. 99XX series seem to have a problem bricking, baterry life not as good and a camera that is subpar.
As for Android, I wasn't impressed with the early incarnation (Hero). Yes the OS has grown in leaps and bounds but for my needs it matters naught. I need something with a physical KB, excellent email, texting and battery life. Having LED notification is a plus.