Here we go, comparision of the processors
Well, the 1.8ghz will give better performance all around, and you would be thankful for it. The 1.6ghz isn't bad either, it does its job, the 1.8ghz, is just an extra boost in performance, just like the difference betweeen the 2ghz macbook, and the 2.2ghz.
As for the hard drive, this is where the magic happens. The SSD is a speed demon. You can open an application, at the same speed it takes my 2.8ghz
7200rpm HD can. the SSD doesnt have moving parts, so it takes faster to open, so i can say that the mba can open applications faster than my speedy imac, but the processor is what matters when your IN the application.
So when your upgrading the space to the SSD, you are looking at 10x faster boot ups, application opening, and loading documents and stuff. but thats it, other than the fact you can move a big file from one part to the other part of the SSD quickly, the HD can do faster sequintial writes though (dont ask me what that is). So, ill repeat
With the SSD, you will see an EXTREMELY powerful boost in speed when opening apps and stuff, i would pay $999 for that, that is a real treat, and that is MUCH faster than the macbook
with 1.6 vs 1.8, with the 1.8, you will see a boost of performance
IN the application, not how fast the system is at opening stuff and documents, performance in the application. and apple makes the 1.8ghz for people who plan to do little imovie, and some multitasking, apple intends for people to buy the 1.6ghz, and expects a lot of people to buy the SSD
my dream mba, btw im not getting one, would be a 1.6ghz, and SSD, the 1.8ghz isnt worth it, but on a macbook, i would recommend the extra .2ghz, on this, nah. the SSD will be a treat, but the less space will be a boo, but, still nice.