I purchased the exact same unit in August and we've had quite the nightmare with failed components on ours, however the dealer was great to deal with and after 4 separate visits (the RV staying a week at a time) all of our concerns had been addressed.
Two things to watch for on this particular unit:
1. Make sure the slides are properly adjusted, ours weren't and while towing during a strong rain our unit took on severe amounts of water that came in between the bottom of the slides (all 3) and the floor.
2. the factory tires are complete garbage, I towed on them once while the new Goodyears where on order and it reinforced my decision to get rid of them asap.
The dealer only had access to the Marathon's so that's what they threw in the deal, however I've had great luck with the Maxxis brand on previous rigs.
we've got around 3000km's worth of towing on this trailer and 25 nights since we bought it, and the layout and functionality of this unit is great with 2 kids.
2013 F250 XTL 6.7
2015 KZ Durango 296BH