Before I got the Trimetric it was hard to know when to stop the generator at the desired battery SOC, with only a voltmeter to go by. It was really guessing. That was a big problem for me. I don't know how others can tell, if they even can. The Vector portable with the ammeter on it was a blessing for that. Converters don't have ammeter displays.
With the Trimetric you can see when you get the batts to Vabs, observe the start of tapering amps, and when you are down to the amps per battery that 'goes with' the desired SOC (if you know that number!)
Even better, you can see how many AH are back in to know if your 50-90 is done. No sense running the gen any more after that.
Big problem solved! :)