I have two bigger dogs, and personally, I prefer no storage in the cab with the full coverage rubber floor mats. Lots of room for the dogs with the seats lifted up. Storage in the back under the tonneau cover.
A couple of dribbles by the tailgate through the car wash. Otherwise dry. Most likely could make adjustment and be 100% dry.
Lomax is having a sale right now and can save over 20%. I am sounding like a salesman, but just a happy customer.
Personally, really like the Lomax. 2 years on and looks and operates new. Super simple to remove and put back on as needed. Would buy again.
I never understood appeal of the rollers. Seems more likely to break and takes up unrecoverable space.
I got a hard tri-fold that had negligible (maybe +1mpg) effect. Maybe the flutter is increasing drag which seems to be your concern. 4-5 mpg is a lot. Over what period of time did you base this on? I will have this amount of difference when comparing city only (16-17mpg) to city/hwy (21-22mpg).
Just rolled over 30,000 carefree miles and still making discoveries. Learned that hitting the "end call" button on the steering wheel while media is playing it acts as a mute button. Same as tapping the power button on the radio. Nice.
Purchased Nov 2020, 5.3L 8AT @ 25,000 miles. Has been perfect in operation unless you count the sticky auto-stop button when it is cold. I think the family spilled some soda on it on a road trip. I should get an disabler for the A/S as I hit that button every time I start it.