I've only towed dry so far (4,580 lbs) and the Trail Boss pulled great. When loaded the trailer gets to 6,000lbs so it'll definitely get more noticeable. This trailer is well within the TB limits so I expect things to go well towing on freeways... even when crossing the Rockies.
I tow a heavy 30 footer. Probably well north of 7000. Then the bed gets loaded with a generator and ice chests etc. The trailer info system says I have over 2,500 miles towing it already. My suspension is stock except for a front end level. It's just a little out of my comfort zone so I am going to put air bags on it to be safe. My 5.3 has all the power I need even in the Rockies. The 10 speed transmission is a dream. I hardly touch my brakes even on step downgrades. You can pick a gear to hold it at any speed you want.
From that one picture yours looks reasonably well trimmed dry. When fully loaded the trailer and truck should both be level. If your rear end squats your pulling too much weight off the front axle. The real test is to get it up to freeway speed and carefully move the wheel back and forth to create some sway. That will let you know how stable it really is. If it makes you pucker there is a problem
Nice rig! I hope you enjoy it for many years. Mine is an old 2007 and still rolling. Spent 4 days at a lake this weekend.
Steve