I've had my Titan gas tank for exactly one month now. My biggest concern was the accuracy of the gas guage... and I'm happy to say it was a non-issue. After you fill up the gas gauge will show full until you use about 9 gallons. After 3 fillups this is what I've concluded so far.
When the gauge shows;
3/4 Full -- You've got about 34.3 Gallons
1/2 Full -- You've got about 24.3 Gallons
1/4 Full -- You've got about 13.7 Gallons
Empty -- You've got about 4 Gallons
Since I've never had a vehicle with a highly accurate gas gauge, these results suit me just fine. Biggest deal for me is I can get about 650 miles between fillups (I hate to see the guage below 1/4 tank). The only thing I'm missing is the money tree to help me fill the beast!