You're welcome.
Just a quick question:
How long do you plan on using this?

And, will this be for you, OR for the entire family to use, OR a gift (and how much you like them?).

Also what is your maximum budget (I will do a quick hunting for you)?

Now what you can do to help me/help you is:
Test out a regular Atom (any N-series) netbook. Just try one from your friend or stroll into a store and give it as much thorough use as you can. (open several folders, play music, open several browsers, play videos etc etc).

Don't worry about the CPU speed (yet).
Can you tolerate the N-series performance?

If you cannot test it, I can tell you it is a different experience from your standard Windows 7 experience.
Eg when you hit a folder, normally it would just open, but on the Atom's it will take a second (or even more depending on the contents) to open.
If you demo this shortly it will be okay, but in day to day use it really takes its toll because you end up with waiting periods.

For some people, this is okay. Not for me which is why I upgraded.

I'm rocking a 1.3GHz Core2Duo (SU7300) which is pretty common now - so if you can find that in your budget grab it!
With the SU7300 folders open swiftly, and applications respond - just like normal (minor times a lag - never a worry).
I'd say the SU3500 is midway performance in between the speed of the N455 and the SU7300. It's is basically the same SU7300 but with only one processor not dual.
So if you cannot bear the lag of the Atom line, but fall short of the SU7300 budget, grab the SU3500 if its in your range.