Okay. Lets put this one to rest.
1) Leisure Pro is NOT an Authorized dealer of Sherwood Products. Any warranty they may or may not offer is 100% of thier own doing. If you have a problem with your piece of gear I can't speak for how it will get handled.
If your LDS, or Authorized Dealer of your choice, has a problem with a piece of gear they are going to call ME about it and find out what to do. It may get replaced. It may get repaired, but you will be comforted in the fact that the Technical Support Department at Sherwood, with 23+ years of experience with the gear, and if necessary, the engineers at Sherwood who design the gear, had something to do with the decision on your piece of gear. Not some box packer who will just cut his losses and send out another piece of gear hoping the problem is not on this one as well.
Again, I can't speak for how LP will handle your problem, but a great example of what you DO pay for at your LDS is this. Per chance, IF your reg had low IP during it's second Warranty Service (what you won't get if you purchase your reg from LP), the Authorized Sherwood Technician can diagnose if it needs a new spring, cap, or bellville washers. Or maybe just a shim. If they get stuck, they can, and often do call me for more intricate advice on how to make your piece of gear work the way it's supposed to. If worse comes to worse, I will authorize it's replacement but not before I check the new piece to ensure it does not also have the same trouble. I cannot speak for what LP or any other Non-authorized dealer knows or does not know, but I can assure you that this level of support does not exist for them when they get stuck.
2) The Oasis is indeed a regulator that was designed with cold water conditions in mind originally a LONG time ago. Longer than MOST (Note I said MOST, not ALL) of you have been diving, and some have been alive. The moisture retention fins were a bit of an accidental find that are designed to combat dry mouth, and have never been advertised as a solution for it. I know we haven't argued that here, but it comes up on this board all the time. The ONLY difference today between the Blizzard and the Oasis is a couple parts in the 2nd stage of the Blizzard are treated in a manor to make them more resistant to freezing up in extreme cold water conditions. Both 2nd stages have the same exact parts in them, and you can make an Oasis into a Blizzard and a Blizzard into an Oasis by simply trading parts. Neither regulator has any additional parts that the other does not have.
Have a great day and enjoy your gear what ever you choose to dive with!