I don't think the lowest end ph's (703/800) are faster in terms of clock-speed.
Even if they are, a couple hundred mhz won't translate to anything in RW terms.
And they only had 512MB last I checked....

The Ace (900/1) may be noticeably faster in some applications.
But rumors point to it maybe not making it out this yr....
It'll have a large 4.5(?)" screen, but at still the same WVGA res, eeish.
I really don't get the huge kudos people are giving Nokia here...

You want a dedicated camera button....
Someone will remap the power button or volume keys so you can have one on the N9.
That's a relatively minor reason to want the 800....