I raced on a Morgan 27 during the 1970''s. In their day these were pretty fast little boats. They were designed around the earliest IOR rule and have some of the quirkiness of early IOR boats.
These boats were reasonably fast upwind, and compared to boats of that era were pretty quick downwind as well. They were prematurely made obsolete by boats like the J-24, Kirby 25, and Capri 25, which were all so much more versatile and so were able to beat the Morgan 27 on all points of sail and in all conditions.
These boats took a very large crew to race competatively. With their small mainsail/ large jib
sail plan they took a very large sail inventory as well. Performance was extremely related to having exactly the right sail up for the conditions.
Build quality on these boats was miserable. They were known for keel attachment problems, rudder problems, bulkheads shifting etc. The shroud configuration on the boat that I raced on was such that in a heavy breeze the topsides with oil can in on the weather side and would pop out as you tacked with a very audible boom. As I understand it many of these boats have been modified to eliminate this problem and that some of the last boats had some kind of factory fix. The electrical systems on these boats were always a problem although some of that may have been related to the owner wired instruments on the boat that I raced on and racing out in the Atlantic we took a lot of water down below.
These were not great light air boats. Neither did they do as well in a chop as the boats like the 1970''s MORC types like the J-24, Kirby 25, and Capri 25 mentioned above.