I put over 100k on a Gen I and have 21k on a Gen II. Both non ES models, so can't help you with the adjustable suspension. I've been told by others I trust that it's very good for OEM stuff.
Considering the '14 on used prices now, I'd spend the extra for a Gen II. The Gen I is still a good bike and if you find a great deal, there are minimal upgrades that can be done to bring it up a bit, but you won't be able to add CC at the OEM level. There are ways to add a very functional CC unit, it's just not plug and play. Same with heated grips, lots of good options, and most cheaper than the OEM for the Gen II. Just stand alone systems.
The Yamaha extended warranty can be added to any bike, as long as it's still under the original 12 month warranty. So left over bikes that were sold late may still qualify. I bought a used '15 a year ago that still had several months of warranty on it and I added 4 years of the YES through D&H in Cullman, AL for ~$400 or so. Any Yamaha dealer can sell you the extended warranty, just make sure to get the Yamaha version YES, unless you can't because of the original 12 month warranty being expired. D&H has the best pricing, but you have to call them to get it.
If you find a bike with Extended warranty on it already, or existing original 12 mo warranty, a dealer has to transfer it to your name. No charge and takes about 5 minutes to do. You will need proof you own it, signed off bill of sale and title is usually good enough, or the DMV paperwork if you've already been there. Most will try to sell you the extended warranty then if it qualifies. If you can get it for less than $500, including sales tax, give the local dealer some love. You may be back there for service and sometimes that helps.