First things first - Starduster, welcome to the Forum! I think you'll enjoy it. The people here are a little odd, but generally harmless.
In its early days Heller was notorious for recycling ship model parts, using one hull, with different details and ornamentation, to represent ships from different countries and different centuries. I haven't seen that "Spanish galleon" kit for many years, but as I recall the hull form was extremely dubious. (Caveat: the available contemporary sources are such that nobody can say for certain what constitutes a truly accurate or inaccurate shape for a Spanish galleon's hull).
Though I've never bought the Imai kit, on the basis of pictures I cerainly agree with Millard that it's a fine one. I'll in fact go a little further than that: of all the kits (plastic, wood, and otherwise) that I've seen and are labeled "Spanish galleons," that one is the only one that can legitimately claim status as a scale model. Revell has, at various times, sold three kits with the "Spanish galleon" label. The 2-foot-plus one, originally issued in 1970, was an historical travesty that, according to Revell's own literature (which I remember reading in the hobby shop where I worked at the time) was designed for "young married couples and interior decorators." According to Dr. Thomas Graham's history of Revell, it was "researched...at the reference library of MGM movie studio." 'Nuff said. A couple of years later Revell issued a smaller version of it that was intended to be mounted on an included "wall plaque" in the form of an allegedly antique map. The smallest Revell "Spanish galleon" was, in fact, a slightly-modified reissue of the company's Golden Hind. As a reconstruction of the Golden Hind it was outstanding, but the Golden Hind was no more a Spanish galleon than the U.S.S. Kidd was a Japanese battleship.
If you're in the market for a scale model of a Spanish galleon, the Imai/Lee/Aoshima one really is the only game in town.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.