I've never had a problem w/ the harness on the Maestro. My d/c lady, the biggest complainer in the world, has never complained about it either.
At any rate, as PP said, it's a continuous harness. That means it's one long attached harness. If it's a problem, just pull it all the way out, jiggle it side to side until even and then tighten.
Oh, I think I know why I don't have a problem, I don't adjust the harness each time. I just adjust it for the child and leave it there unless a thick/thin sweater makes it too tight/loose and then I'd adjust it a click or two.
I *love* the Maestro for a travel and back-up seat. It's light and easy to install. Light being really important sometimes for a temporary seat. Last week, I got my car interior cleaned. Friend picked us up. I told the Frontier out of my car and put the Maestro in. I didn't want car guys touching our car seats. We got there, ODS carried his booster, I pulled out YDS's Maestro. Then, YDS went into another seat in friend's car and ODS went into the Maestro. It had to go into the 3rd row, through the back. Then, booster went on the floor. It was *perfect* no way I'd have been able to do that w/ the Frontier. That I left on the floor in our play room for the day. Then, left the car empty to dry the next day before putting the Frontier/Oobr back into our car...
Yep, LOVE the Maestro for a spare seat, figure out the harness, it's worth it.