I have Vetus bow thruster fitted and I wouldn't fit another one. Its under the bed in the forecabin and when we removed the cover to replace the brushes in the motor the whole place was covered in carbon dust, it took a whole afternoon to clean the mess and our clothes had to be dumped.
After all the cleaning, replacing brushes we used an old bedsheet clipped like a tent over the motor which allows it to breath but still catch the carbon dust.
Read the small print on the brushless motors thrusters, you'd assume they'd run much much longer being brushless, in fact where the old motors had a thermal cutout and shutdown, instead of a thermal cutout shutting down the motor the brushless close down to half power.
The other problem I have with them is the fact they use a plastic propeller which goes brittle over time and the blades break off.
When this ones expires I'm going to fit a p.t.o. on the gearbox and fit a hydraulic one.
Thats just my experience with them.