Lotta experts here ...
I had a friend who bought a AJ28 flybridge with gas power that keeled walked badly over 20knts. I mean bad, if a 20ft boat went by, you would fall of the edge of the earth and end up in a black hole facing who knows where. We had to cut the bottom three ft wide to take out the small V on the bottom of Duffy hull to flatten the bottom, plus trim tabs and that helped. Fit and finish was good except the window edges were not decored and was wet. One other thing I did not like was the fiberglass fuel tank was a tub that only had 2 layers of glass over the top. Scary as it was more flexable then a rubber bladder though it did not leak but with gas, if it did

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Let's see if we can make some sense out of tunafishhkg's post above.
You mention the AJ 28 and Duffy in the same breath - which is it? AJ originally finished Duffy 26s but then designed their own hull, the AJ 28 - these are two different hulls (a fact that you seem to have missed).
Regards the evil handling tub that you cite, I'd just point to 50+ mph race boats that tore up the lobsterboat racing circuit in their day (better than ten years ago now). Ever hear of the Terminator? How about the Lunasea? I'm sure everyone here has seen the photo of the upended lobsterboat at the Searsport venue ten years ago now, right? Well, that boat that went airborne (and then sank) was Jim West's 'Wild Wild West' (Jim's own design). Anyone here remember the other boat in this two-boat match? The one that didn't go airborne and sink? Well, that was the Lunasea, an AJ.
Finally, like just about all Maine builders, AJ sells kit boats and I'm certain that if you put just a bit of research into it you'll find that you friend's mickey moused mess was rushed to launch by some shade tree 'finisher'. And while its true that many a downeast design can use trim tabs, the AJ is as stable and flat riding as the best of them.