I need to start with a big caveat: I haven't seen the inside of the Academy box. I do, however, have some recollection of the original Pyro kit. I'm assuming the Academy kit is a reissue of the old Pyro Charles W. Morgan. If that's not the case, for heaven's sake ignore all the following.
The Pyro kit was part of the company's rather large "dollar series" of sailing ships that were released in (I think) the latter part of the sixties and the early seventies. It was quite a big range, including famous European and American warships and merchantmen and some exotic craft, such as an Arab dhow and (I think) an Indonesian vessel of some sort. They were characterized by low parts counts, heavy detail ("wood grain," etc.), and injection-molded styrene "sails" that were cast integrally with the yards and other spars. They also had injection-molded shrouds and ratlines and, in some cases, injection-molded flags. I have the impression that the series was intended primarily for the kids' market. The "sails" particularly turned me off; I bought a couple of the kits and looked at some of the others, but I don't think I ever took the trouble to finish any of them.
My recollection is that most of those I looked at suffered from one or more serious shape problems. I have a vague recollection that the Morgan's hull was too skinny, and was pinched together at the stern. That, however, may well be my Halfzeimer's-afflicted memory talking.
Those kits probably were instrumental in introducing lots of kids to the history of ships. If the sails and spars, the shrouds and ratlines, and some of the cruder detail parts were thrown out, and much of the cast-on detail scraped off, it probably would be possible to use one of them as the basis for a serious scale model. I question, though, whether it would really be much more difficult or time-consuming to start from scratch.
For those interested in nineteenth-century American whalers, there's good news: Revell Europe has announced that it's reissuing the old Revell Charles W. Morgan: http://www.revell.de/en/products/model_kits/model_kits/ships/?id=208&KOKANR=01&KOSCHL=03&KGSCHL=02&L=1&page=2&sort=0&nc=1&searchactive=&q=&SWO=&ARMAS4=&PHPSESSID=a045e91c3e4ce4ea4d81502ca98dd6a3&KZSLPG=0301&offset=13&cmd=show&ARARTN=05094&sp=1
For the benefit of those who don't remember it, this is one of the nicest sailing ships Revell ever did. It's small, but the detail on it is outstanding. (I do wish Revell Europe would hire somebody who's literate in nautical English to write its web advertising copy. "Pinnaces"? "Flenching stage"?)
The Revell kit does present two problems - neither of which should deter potential purchasers much. First, and most irritating, is the way Revell handled the whaleboats. Their hulls are beautifully done, capturing the subtle shape of the originals admirably. But of the seven boats provided in the kit, only two have detail in their interiors. Of the remaining four, two are supposed to be stowed upside down; the lack of interior detail on them won't be noticeable. But the ones on the davits are supposed to have their interiors concealed under vac-form "covers." That just isn't how whaleboats were stowed.
In other words, to make the model look like a real whaler the modeler would have to either (A) leave off three of the whaleboats (maybe they're off after a whale), (B) scratchbuild three interiors (difficult, though by no means impossible), or (C) buy two extra kits (expensive).
The other problem is that the kit is based on the real ship as she was configured when the kit was designed. The original issue date (according to Dr. Graham's book on the history of Revell) was 1968. At that time the folks at Mystic Seaport were interpreting her as they thought she had looked in the 1850s or thereabouts: rigged as a full-rigged ship. She also, in those days, had a color scheme that included phony "gunports." Generations of Americans grew up taking it for granted that the Morgan looked like that, but subsequent research established that she never had painted ports during her active whaling career. (The "ports" apparently were added after her retirement, when she was being fitted out to star in a movie.) Since then, Mystic has restored and refurbished her several times in an effort to make her look like she did in the 1870s and 1880s. (Reason: the researchers have quite a few photographs of her from that period.) She's now rigged as a barque - i.e., with no yards on her mizzen mast. And the phony gunports are gone.
The modeler working with the Revell kit therefore would have to make some decisions. The original release had a painting on the box that showed the painted ports, but the designers resisted the temptation to mark them with raised lines on the hull moldings; painting the model in the ship's current scheme would be easy. And it probably wouldn't be too difficult to convert the mizzen mast into the barque rig. I suspect some smaller details would need to be changed if the modeler wanted to reproduce her current configuration precisely. (For that matter, the Morgan is undergoing yet another restoration right now; she'll probably emerge from it looking different in some way.)
I'd strongly recommend the Revell kit over the Pyro/Academy one. But to each his/her own; anybody attempting the smaller kit certainly has my best wishes.