I will start with the topic of the original post (and the last point raised in your last post). The original poster specific questions, "Is this a well built boat? How do they perform? Are they hard to handle?" and at the heart of it my comments were aimed at addressing those questions. I included additional commentary to explain my possition.
Perhaps to be more helpful I would should have suggested that, if J &S want a similar priced, well-built, full keeled or long keeled, easily handled, that offer similar space down below, a similar layout, in a more manageable package they should look at smaller boats with a similar waterline length, perhaps they should look at a boat like the S&S designed Hughes Northstar 40, CSY 41, Gulfstar 41, Moody 39, Tartan TOCK, or Whitby 42 for example.
When I say that the Morgan 45 was a CCA Rule beater (or that any CCA era boat design was corrupted by the racing rule) I am referring to several specific aspects of the CCA rule that compromise the sailing ability from the standpoint of motion comfort, seaworthiness, carrying capacity, and performance.
That definition of the CCA rule ("considered length as the basis for the rating and then had adjustments for beam, draft, displacement, and sail area, plus correction factors for stability and propeller
.") is a little to terse to explain the issue. For example, under the CCA rule length was defined at the waterline, and not at the length on deck. The CCA Rule over penalized waterline length far more harshly than the real life advantage of having the additional length. There was a lopsided advantage to building a boat with as short a waterline length as you possibly could. A few feet of waterline length might give you an 18 to 21 second a mile rating change but only affect your real speed 12 to 15 seconds a mile. Changes to the rule after Finesterre made the advantage of an excessively short waterline even greater. To beat the rule, CCA era boats with racing intentions reach a point where boats like the Morgan 45, had a waterline length that was 2/3 or less of its overall length. It is important to note that cruising boats of that era, traditional sailing working watercraft, and even modern cruising oriented boats all had waterline lengths that were somewhere around 85% (or more) of their lengths on deck.
When you look at studies of seaworthiness and motion comfort, both in model testing, in studying actual storms, and in instrumented examinations of actual boats, to one degree or another, they all point towards waterline length as being a prime determinant of a boat's seaworthiness and motion comfort. Obviously, there are other factors as well, but no one factor somes up as consistently as waterline length, with the possible exception of vertical center of gravity relative to the vertical center of buoyancy.
Which brings us to the next area in which the Morgan 45 was a rule beater. In order to reduce the modifier for stability (which was measured by hanging a weighted in a bucket of water and then measuring the movement when a weight of a known quantity was moved a known distance athwartships) the beam of the late CCA boats were purposely reduced below what would have been considered a moderate beam for its day. To beat the penalty for stability, and draft designers produced boats that were particularly tender. Short waterline lengths and narrow beams tend to produce boats with small waterline planes which in turn produced deep canoe bodies. This makes for a boat that again is compromised from what is ideal in terms of seaworthiness and motion comfort. For although some of these boats like the original Morgan 45 carried lots of very dense ballast moderately deeply, the distance between the center of buoyancy and the center of gravity was quite small compared to what was typical in cruising boats of that era and more modern craft designed for offshore use.
It is true, as I have experienced and other CCA era boats will note, at a certain point of heel, as the topsides are buried in the water, the boats seem to stiffen up. This occurs because the as these narrow beam, deep canoe body boats heel, pushing the topsides into the water quickly moves the center of buoyancy outboard and begins to generate a lot of form stability. The short coming with that is you end up with a boat that has wide roll angles due to its high center of gravity relative to its vertical center of buoyancy and a boat with a relatively quick motion when heeled due to its high form stability in the heeled postion. When coupled with the propensity towards pitching, it makes for a boat with poor motion comfort compared to boats that were designed as cruising boats.
The last and possibly most significant aspect of CCA rule beating is what it did to sail plans. Prior to the CCA rule, small boats that were designed as cruisers, race boats, and that were designed as working watercraft, generally had either sloop rigs with big mainsails and small jibs (oft times multiple small jibs). But the CCA rule (for reasons explained in other posts) chose to only penalize mainsail area, without even measuring headsail or mizzen areas.
As a result the standing sail areas were greatly reduced to historically low, SA/D's. This meant that CCA era boats went to untaxed, very large overlapping headsails over come their small standing sail plans. Large overlapping headsails are just plain harder to handle. You are right that you can go to smaller overlap jibs, but when you do the already poor light air performance of these boats drops further. In the case of the Starratt Jenks, you can modify the rigs to make them better handling and beef up the steering to reduce the loads, and add bigger winches to make the headsails easier to handle, (and I aluded to that in my answer citing the Owner who added a bowsprit, and by noting that prior owners may have modified their boats to correct short-comings) but the point is, in their more normal form, these are not easy to handle boats, and that was the question. And a big part of the reason that these are not easily handled boats comes from design compromises made to beat the CCA rule.
I grew up sailing CCA era boats and continue to sail on them to this day. I get to compare them side by side to other designs that predate, and post date their period. I don't have a bias against the CCA rule per se but I am a big fan of boats that are designed to sail well, which in my opinion generally means boat designs that were not compromised for any arbitrary rule. CCA boats have their own sailing aethetic and are fine for coastal cruising, but in my opinion, given the global set of choices out there, they are not particularly ideal for anything, which is why I use the term obsolete.