We sail a 1986 First 42, shoal draft version (i.e. 6.5'), and the yacht is without a doubt one of the best boats we've ever been aboard (in 52 years). They are built like brick shoot houses, good looking, and unusually fast. In any wind we can assume we'll average 8 knts and even in light air, with an assym, we use 6 knts as an averge speed for calculating passage times.
If the boat you're looking at has been reasonably well maintained by the prior owner, you'll be glad you've bought her. The yacht has few vices if any save for the fact that one needs be patient as a lot is squeezed into small spaces. Working on the engine/transmission can be a trial until one learns the tricks. On the other hand, the Perkins 4-108 is a very sturdy engine and unusually reliable so it's usually just routine maintenance.
Our "crew" is a mid-60's man and a late 50's woman (that displaces all of 100#) yet we have no difficulty handling the yacht, even in foul conditions, and have managed passages without undue difficulty of discomfort while other yachts have hove-too or withdrawn from the same passages we've made. If a 5' tall, 100#, woman can handle the yacht on a night watch in rotten weather, it says as much about the yacht as the woman, no?
"It is not so much for its beauty that the sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."