My .02s , I have a Fass TT SS 95 and have it feeding from a S&B 52 gallon tank for the Crew Cab Short beds, with a built in sump port and return all half inch. I've had this setup just over a year on the Fass and less than a year on the S&B tank.
My beef with the Fass is that my half inch lines that were provided in the kit are already starting to crack on the outer enamel for the price I paid I'm not happy otherwise it's a decent system, I'm not a fan of their drainless water separator that will just cause a no start when it's full of water. I've had that happen with the provided filters in the kit although my fuel was clean since I regularly drain my water sep. Never again ~
My knock on the S&B tank is the design over the OEM tanks baffles and venting and the features it advertised. Specifically the lack of tank baffles (not sump baffles it has those) for fuel slosh. When you factor in the increased capacity and the weight (364lbs full roughly) that comes with it, it's a pretty asinine of a design. On a full tank I snapped a sway bar from the body roll making a turn in the rain. Additionally because there aren't any tank baffles the venting system is very sensitive to all that fuel slosh. I can't fill up on the High or medium pump flows, only the minimum making it take forever. Any faster and the vapors will trigger the pump to cut as if it were full.
The return port is a gimmick in my opinion, it's on the top of the tank because it's just a copied design feature for their in bed transfer tank units. Because the port is in the top of the tank, my mass flow return coming off my Fass is now waterfalling fuel from the highest point which isn't so much an issue if your full, but near a quarter tank that "aeration" is a real issue. Speaking of quarter tanks, don't accelerate hard near that level, the fuel slosh again from lack of baffles on a much larger tank becomes an issue as your feed port at the sump is now sucking in air till it settles which you will noticeably feel as the Truck will buck or stutter as if you're out of fuel. Keep in mind according to the service rep I spoke to when the fuel light comes on you still have 7-8 gallons reserve. But the slosh at a quarter will make you fill up long before that. They advertised these ports being built for aftermarket lift pump systems but some points of their construction are pretty backwards in complimenting a Fass or AirDog.
Lastly, when I got wind of this tank coming out it was still in R&D, I had only seen their tank featured on a product review by ThoroughBred Diesel for a Powerstroke. I was so impressed by the features on that tank I reached out to S&B and requested to be put on a preorder list before it came out of R&D and prepaid mind you 1300 bones. My mistake. I would be one of the first few to install this on an early 03 truck which they did not have a completed install guide for as they forgot to mention that my intake sending unit (only used for the factory hardline return) would not be compatible as the early 03 04 trucks used the previous generation intake sending unit dimensions, and that I had to get a new sending unit sized for the later trucks specifically an 07. One Delphi sucker punch later, the tanks provided vent and feed hose weren't long enough out the box.
For my driving and fuel economy numbers I get average 750 miles a tank over 480ish on the OEM 34 gallon which is the only plus besides being able to put stickers on the bottom of the tank as it drops down about 2 1/2 inches lower than stock giving you justification to lift your truck to "compensate". Which now that I think about it with my factory tow rake, A level or lift would probably help my fuel slosh since the sump is at the rear....
I've dropped this tank trying to install it 3 times each time discovering they had overlooked something or not provided the right information/ parts. In total I've dropped my fuel tank 7 times, I can now solo a tank removal and install at a quarter tank in an hour and a half tops in a driveway. I've yet to email their service rep I've been in contact with since my preorder to give my thoughts post install with some time on it but I will shortly. I continue to have so many other pressing issues with my truck that need attention. But if they come out with an improved design that fixes alot of the flaws I listed above and not allow me to swap and pay the difference I might have to make a 3 tank cross country trip to their headquarters and speak to management directly.
Attention: TDR Forum Junkies 
