My opinion. If they offer bigger, get it. If they offered a 20k AC, I'd have it. ALWAYS better to get too much than not enough, and ALWAYS cheaper to get it from the get go than to have it installed later. If you live in the south, a 13.5 AC should be outlawed. 15k ac should be standard, if not 2 or 3 of them depending on rig.
John and Rebecca Dickson
Emma-8 / Little John-5 / Iva-1+
2013 Ford F-350 Lariat FX4, CC LB PSD, DRW
2015 Jayco Jay Flight 28BHBE (#8)