2011 ISX 525 Cummins okay motor? (with DEF)

We are looking to upgrade to a CA compliant truck and have found a 2011 KW W900 that we are very interested. We currently own a 2001 KW W900 which we bought new and it has been an excellent truck with very low repairs. I know we are walking into a big change with the upgrade, but I've been researching for my husband as much as I can and as quickly as possible. I contacted our local KW dealer and had them run the VIN on the truck we found and he said everything looked really good. There were only a couple minor repairs done while under warranty and nothing that stands out for engine work. It has about 320,000 miles on it. From what I've read, it is the 2008-2010 that had the most problems, but I'm wondering if anyone has any input on the 2011's? We understand we will probably have to spend $2000 every year or two on extra maintenance, but I'm hoping we can have a good truck if we maintain it properly (provided we know how to maintain it). Any tips? (Besides stay out of CA).

Thanks!
Cher M.

 

Thanks for the info everyone! We put $ down on it so hopefully it's a good one!