The new changes offer some new features in the nat functionality (The major one that I am excited about is static PAT for a range of ports instead of having to do one at a time)
The changes are radical at first, but after some time with 8.3, I'm beginning to see the benefit of what these NAT changes will bring.
The other major thing that was changed was the ability to do global access-list, which should allow for greater functionality.
I can't really tell you which OS version is best because it is dependent on your network scenario. I would urge you to read the 8.3 release notes and see if the functionality changes are something that you are interested in, then weigh whether or not 8.3 is a suitable fit for your implementation at this time.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...