I had a Lagoon 390 1991 model, this was the owners version with single aft cabin.
I sailed her over 10,000Nm in one year, through Biscay storms in November....Caribbean and back in a wide variety of weather conditions and temperatures.
Fantastic boat, sails really well, well built, great deisgn features like the large hatches over the rear cabin, and lockers in the swim platform ideal for storing petrol and rubbish....only downside was some of the internal wooden panelling squeeked as it is mounted into grp channels in the internal mouldings, but it was easily cured with silicon spray.
I'd buy another one and take it any where.
I realy can't think of any bad points apart from the fact that the standard cookers didn't have a grill!!
Hope you've found a nice one, mine was a lightly used, well looked after one. I guess the twin aft versions may have been chartered so could have suffered from more wear and hence shown up any weaknesses.