I don't have any thrusters. With twins, wouldn't ever use one. My last boat, however, was a Cooper, Seabird 37, sail, with a long shallow keel, single screw behind a barn door rudder.
Now that is a combination that is doomed to back as accurately as a game of chance. If I had a stern thruster I would have used it. Had I done so, I never would have been as frustrated, and I never would have learned how to manage any boat, without a thruster, in tight situations, where I needed it to go where I wanted. I recall having to leave a crowded dock in a strong cross wind, where I had to get from a side tie at the dock, out past boats rafted onto the ones in front and behind me, into the channel, then back all the way down the finger before being able to turn around, all in a strong cross wind. No opportunity to practice, but getting aggressive on the boat speed in reverse was just the ticket, and after I learned that little trick, using the rudder to actively steer in reverse, I never looked back (pun intended).
Since then I have taken the challenge with several power boats, in tight manouvering, and once you think about the physics of it, there is absolutely no need for a thruster.
Practice.
Better if you can practice where there are no $M bits of plastic where you might stray.
The first trip when my present boat was new to me, coming dockside where the current from a nearby river mouth affects the docking, I came alongside but told the willing hands on the dock to go back to their boats, as I was practicing. Just a couple of tries and I became proficient enough to do it in front of a crowd without flinching, no matter what the wind or current conditions. You just need to pay attention and try to understand how wind and current are affecting your boat. The satisfaction you will get from mastering the peculiarities of your boat is worth more than the little extra control a thruster might give you.