Ours is a 4 wheel drive 6 cylinder. We ordered our trailer with the higher axle clearance so the trailer would sit more level with the truck's height. As well, my husband dry camps almost exclusively when hunting and fishing so he's often going off paved roads onto dirt roads.

As for sleeping space, it seems adequate for us but we are both under 5'8".
It might be tight for 2 taller people because of the length of the bed. When he's on his own, he usually sleeps on the single and leaves the large table set up. When he went hunting this month, the temperatures were so low that he used the double bed instead - the heat from the furnace hits it better than it does the single.

We purchased a 17 for a few reasons. I dictated the size because I didn't want to have a trailer parked out on my front driveway all year. We paved down the side of our house and are able to push the trailer in and secure it behind a gate. Secondly, my husband wanted something easy to maneuver especially when off paved roads and thirdly, we didn't want to have to buy a new tow vehicle. The 17 met all these requirements and we are more than happy with our decision to purchase it. It's spacious for one person and very comfortable for two.