I use both. The refractometer is great for fling frequent samples during the mash to see if the target is being met. It uses only a couple of drops and if properly calibrated with distiller water works well with built in temperature compensation - so I can take hot wort, cool it a few minutes then test.
It is also robust and since you are not stealing a jar full of wort and dumping it or putting it back in, you lose little and avoid potential infection points.
For the measurements of record, the refractometer is hard to read consistently, so I use the hydrometer there. Also the refractometer needs the SG to work out the FG, so if you interpret off a little at each reading, you get double error potentially.
During fermentation, I can take daily readings with the refractometer without waste until is settles down.
To protect the hydrometers, I use them less and carry them in a drywall tray, filled sanitized, so they arebnot out in the boil area, and cushioned by liquid. I also use a bottling hydro with a finer scale for the FG, as I want to know the real details of the final nectar.