We looked at both the 3655 and the 3600. We really like the rear den because it gives you more of a home feeling with 3 separate areas. The 3600 does have a lot of kitchen counter space while counter space on the 3655 is rather limited. When I pointed this out to my wife, she reminded me that when I retire she is too, so lack of kitchen counter space should not be a problem. I like that the galley area on the 3655 is not on the slide-out, as on the 3600. You can get to the fridge without opening a slide on both abd both have separate desk and entertainment centers instead of a slide out tray. This would allow me to have an electric fireplace on without toasting my knees. While both of these models are in the same basic box, we both liked the looks and feel of the 3655 rear den.
What we really-really liked was that so many things that are extra options on comparable brands come standard on the BigHorn. We have been looking for that perfect fifth wheel with everything we wanted in it but wouldn't kill the truck or the budget -- but that doesn't exist. The BigHorn comes close.
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