No, I wasn't surprised at all. Here are the numbers I used prior to purchasing based on research I did here after people actually weighed their rigs. There has been a lot of discussion about Arctic Fox weights, so there was a lot of it. I figure it is +- about 100 lbs. Accessories like A/C and solar panels weigh a lot, and it adds up. This assumes you have A/C and other common options like the Fox landing, and these are wet weights with full water, propane, and 2 batteries. This matched up very well with my experience with my AF 990:
811: 4,480
990: 4,700
992: 4,800
996: 4,980
1150: 5,050
1140: 5,150