I think the difference between the Allied Princess and the IP27 in terms of tacking ability is largely a function of the overall design of the keel and canoe body of the hull. If you look at the hull forms and specifications for the two boats, it is clear (at least tom me) that the height of the keel proper on the IP27 is larger relative to the canoe body than is the case for the Allied 36. The IP has a relatively shallower canoe body. That is reflected in the D/L ratios (250 for the IP and 309 for the Allied). Also, the forefoot of the IP27 keel carries much farther forward. Basically there is a straight line from the fwd keel base to the leading edge of the waterline. In contrast the forward edge of the AP36 keel is more nearly vertical so that despite the overall relative length of the main body of the keel being longer on the Allied than the IP, the forward edge of the Allied keel is farther aft. Rudder placement, which is further forward on the Allied may also be a factor. I think the cut away forefoot on the Allied is what allows it to come about more easily than the IP. That said, I do always back wind the jib to speed up coming through the wind on my Allied.

Looking at the rest of the specs. The IP27 has LWL of 24.25', a beam of 10.5 feet, LOA of 26.5 on deck and a displacement of 8,000 lbs. In contrast the Allied has LWL of 27.5', a beam of 11 feet, LOA of 36 on deck and a displacement of 14,400 lbs. It is noteworthy that the Allied as a length to beam ratio of 3.25 while the IP's ratio is 2.52. Basically the IP is a fat tub of a boat while the Allied is a relative greyhound. The tubby nature of the IP will certainly impact its performance under sail. Of course, the IP's beam gives it a lot more accommodation space for its length than most 27 footers.