I have a 52 gallon Titan tank in my 2500HD. I had it installed about 8 years ago. It has been perfect in every way. Best money I have spent. The original 26 gallon tank just didn't get the job done when towing heavy.
The only difference I noted is that my low fuel light used to come on when I had approx 5 gallons left. After the Titan install it comes on at approx 10 gallons left. Also the computer still thinks I have a 26 gallon tank so it always shows half of the remaining distance to empty. I have been told I can have the ECM reprogrammed to change this, but I can multiply by 2 in my hear pretty well. All other computer data works fine.
I highly recommend the Titan tank.
2006 GMC 2500HD CCSB 4x4 Duramax/Allison, Titan 52 gallon fuel tank, Prodigy Controller, B&W Companion Hitch
2010 Jayco Designer 35RLTS, Cummins/Onan RV QG 5500 EVAP, Progressive Industries EMS-PT50C, TST Systems 507 TPMS, RV Flex Armor Roof