There are huge difference between ASA IOS 8.2 and 8.3 in terms of NAT, ie: from version 8.3 onwards, the NAT concept and configuration has been transformed, and it's completely different to the OS version 8.2 and below.
I would suggest that 8.2.3 is a much stable version compared to 8.3.2 simply because OS 8.3 is newer version of software with major changes which still going towards maturity. However, if you would need funky NAT then version 8.3.2 would provide you with much more flexibility.
In terms of case load, both OS would be able to handle LAN-to-LAN VPNs very well as it's common deployment.
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...
[toc:faq]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 and UDP are I...