I did it. I bought another carseat. I have had a True Fit, but I bought a True Fit Premier. The TFP is now Sofi's primary carseat.
What's the difference between the True Fit and the True Fit Premier? The TFP has an anti rebound bar (arb). In a frontal crash, a rear facing carseat will rotate downward, towards the front of the car/ the floor. Next it will rebound back up, towards the back of the car. The ARB will reduce the amount of rebound.
With the original True Fit, it can be difficult to access the harness adjuster. It can be buried in the back of the vehicle seat. The TFP doesn't have the same problem because of the arb.
Like the original True Fit, the top of the carseat can be removed until the child is 22 pounds, or the head is within 1 inch of the top of the seat. After the top is put back on, the child can remain rear facing until 35 pounds, or the head is within 1 inch of the top of the seat. The True Fit and True Fit Premier have the same weight and height guidelines. I'd be surprised if a child outgrows this seat by height before reaching 35 pounds, because the seat shell is so high.
The Original True Fit has a line on the side, that says it should be level with the ground when rear facing. The True Fit Premier has a different level guide. On the front, above the harness adjuster it has a rolling ball and 3 sections. One is labeled with X, meaning it's over reclined. Next is labeled with 1 which is where is should be at 45* for a newborn. The last section is labeled 2 which is 35* for an older baby or toddler. The TFP also has a recline mechanism to help with achieving the correct recline angle, though sloped vehicle seats may still need a rolled towel or pool noodle.
The True Fit and True Fit Premier both have lockoffs for rear facing and forward facing. The lockoffs are helpful when using the seatbelt to install, but the also muct be used when using the LATCH to install. I don't find the rear facing lockoffs to be much trouble, unless I'm trying to get a 45* recline. Then the seatbelt or LATCH belt want to slide down, where the lockoff closes.
Both the True Fit and True Fit Premier have a no rethread harness. It has a yellow knob on each side of the seat. You pull them out a little, and slide the harness up or down, to the correct position. For both seats, the harness can be used in slots 1, 2, or 3 for rear facing and slots 3 and 4 for Forward facing.
Both seats also come with infant padding, that can be used until the child reaches 22 pounds. This infant padding helps the seat fit newborns well. Both seats also have a forward facing weight limit of 65 pounds. They have top harness slots of about 17 inches, which should get most children to a good booster age.
Overall, I really like the True Fit Premier. And I do like it more than the True Fit.