I have small hands, and it may just be my imagination, but I would swear the button is just a little easier to push the 2000s.
The bottom cap doesn't screw on as far with the magnet on the 2000, and I don't know that there is that much difference in the hit/contact. I don't know that it's "better". It is better with the 1600s.
Edited to add:
If I can post this here, here is where I got mine, and they have other batteries as well:
AltSmoke.com | Personal Vaporizers | Electronic Cigarette | Ecigs | AW IMR18650 2000mAh LiMN Rechargeable Lithium Battery
Thank you for the link. I have some on order now. They should be here in a few days.