The modern ones with synthetic seal and a bit more stroke can be made to behave quite well.
I'm using a JM/ARH spring in mine, on tight fitted guides, plus JM piston seal and a rear delrin ring on the skirt of the piston- it is a very nice gun.
But the gun really has its shortcomings, with the long transfer port and the large diameter piston.
If you are buying for nostalgic reasons and understand the guns shortcomings, get one.
If you want an efficient accurate and tuneable shooter, get a HW99, 77 or 97.