I had a 390 a few years ago, and met a few owners of 320's all around 1988-1991.
They are well built and designed boats. The standard and size of fittings is far superior to any of the more recent cheaper plastic boats. My understanding was that at the time they were trying to compete with the Scandinavian designs, and were built to a similar quality.
I wouldn't hesitate to buy another one of that range, they also (at least on mine) had some very nice features, like carbon cross beams, Kevlar reinforced bow area for impact strength. Lovely solid wood interior, lots of ventilation.
Really first rate heads, German Reinstorm or Rheinstorm, biut expensive for spares but all metal construction pumps etc.
Problems to look out for are head lining falling off, as the backing foam crumbles, Cable routing through water tight areas, like for'd nav lights through deck locker, ours leaked slightly, just from age and movement.
The off white gel coat takes a bit of getting used to especially when parked next to a shiny new white boat.
Very well built as said before.However look at the keelbolt washers.On a 30Plus of 1992 owned by a friend we had to relaminate and fit biger and wider washers because the original ones were fitted through the fiberglassing that connected the floor grid to the bottom.The result was that the weight of the keel got the structure unstuck.I have good photos I can e-mail you.
Apart from that ,very good boats but undercanvassed IMHO.
I'll have the pics next week and can then E-Mail them to you.There were two Bavarias 30 in Portugal and both had 7/8ths rigs that were too small.One had an in mast furling main.IMHO-in my humble opinion.