Absolutely without question it will be sharper than an OOTB Kasumi...well, wait....we're talking about these, yes?http://www.chefknivestogo.com/kasumiknives.html
If so, then yes....see above.
And 52100 will keep an edge longer than VG10 in my experience, but it depends on what kind of edge said sharpener puts on it too.
A better knife in that range would really depend on what you're after in a knife.
Can you fill in some more blanks?
What other knives have you used?
What did you like/not like about them?
What draws you to these two knives?
etc, etc etc