I'd have trouble deciding which approach to shrouds and ratlines looks worse - the plastic-coated thread or the injection-molded parts. To my eye, both look awful.
Either approach could be made to look a great deal better - if Revell took the trouble. The big problems with the plastic-coated thread approach are that (1) they're so difficult to get taut (though the smaller kits are worse in that respect than the big ones); (2) they don't look right where they're secured to the mastheads; and (3) the "shrouds" and "ratlines" are the same diameter. (The shrouds should be much heavier than the Revell versions, and the ratlines should be lighter.) I don't know exactly what technical problems may be involved in producing those things, but it seems like it ought to be possible to make the shrouds and ratlines in different diameters. (The other two problems may be endemic to the system.)
I think injection-molded shrouds and ratlines probably could be made to look pretty effective - if, again, the manufacturer would make the effort. The ones I've seen in the small Revell kits are ludicrously heavy, and seem to have been formed in molds with the detail cut in only one half. (One side of each "set" of shrouds and ratlines is flat.) Given the fantastically fine detail that's possible with injection molding these days, it surely would be possible to mold them in such a way that (a) the diameters of all the lines were much closer to scale; (b) the ratlines were thinner than the shrouds; and (c) the ratlines sagged between the shrouds.
Lindberg, in its two forays into the sailing ship realm back in the sixties, came up with a solution to the Great Ratline Problem that, I think, showed promise. The shrouds and ratlines of the Lindberg Wappen von Hamburg and La Flore (currently being sold as "Captain Kidd" and "Jolly Roger") were molded in a soft, stretchy plastic - something like polyethylene or vinyl. The idea was that, when they were installed, they stretched a little, so they were nice and taut. (And the ratlines were molded so they "sagged" between the shrouds.) In these particular kits the parts don't fit really well, but I think the basic idea was sound.
Back in the fifties and the early sixties, the sailing ship kits in the Revell line were (arguably) the most sophisticated plastic kits on the market. That's no longer the case. Revell hasn't produced a genuinely new sailing ship kit in thirty years, and during that time the technology in other segments of the plastic kit industry have advanced by leaps and bounds, leaving the sailing ship kits as relics of another time.
My observation in my last post that the Revell rigging diagrams are simplified was not intended as a criticism - just as an acknowledgment of something the newcomer ought to be aware of. In the second paragraph of that post I said: "The simplifications are intelligent, but the designers were working within the limitations of the plastic kit and aiming at the typical (or somewhat-more-advanced-than-typical) modeler."
In my opinion the ideal approach to sail plans in model kits is the one Model Shipways has occasionally used. The sail plan in the MS Phantom kit, for example, shows all the rigging and all the rigging fittings that were in the actual ship - and a separate sheet offers suggestions for simplifying those fittings, for the benefit of the less experienced modeler. In casting its blocks with integral strops, Revell was using the most practical technology of the time. Imai, more than ten years later, demonstrated that it was possible to cast a block with a hole through it and a groove around it for the strop. Revell in 1965, couldn't do that. I do think the kit could have had more different sizes of blocks. The big Heller kits do - though that's one of the few points they have to recommend them over the Revell ones.
RedCorvette's observation that the modeler is free to replace the blocks, deadeyes, etc. in a kit is, of course, correct. (I've said for years that most modelers would find they can rig their own ratlines if they'd give it a try. It doesn't take nearly as much skill, time, or patience as most people seem to think - especially in the case of the big-scale kits.) I have to confess, though, that the absence of rigging fittings in such kits bothers me more than it used to, for one simple reason - money. It was one thing to buy a Revell Cutty Sark for $10.00 and spent another $20.00 on blocks and deadeyes for it. Nowadays the kit costs close to $100.00, and a full complement of blocks and deadeyes from Bluejacket would cost $200.00 or more. Even with inflation taken into account, that's quite a chunk of change - especially for a newcomer.
It's interesting (if depressing) to speculate about what the modern sailing ship kit would look like if that phase of the hobby had kept up with the others. A few months back I bought, mainly out of curiosity, a new Dragon Sherman tank. It has over 600 parts. The modeler can choose between plastic and aluminum gun barrels. The suspension system has scale springs. The tracks have individual links - made in a special mold that virtually eliminates sprue stubs and ejection pin marks. The fenders and engine grills are represented by photo-etched brass parts. The tiny machine guns have hollowed out barrels. Etc., etc. No sailing ship kit on the market - plastic, wood, or otherwise - demonstrates such a level of sophistication. If Dragon, Tamiya, or Hasegawa were to put that kind of technology and ingenuity into a sailing ship kit....Well, we can dream.
I suppose the market isn't big enough to justify such an undertaking, and probably never will be. There probably will always be more aircraft and tank enthusiasts - and a first-rate airplane or tank model, after all, doesn't take as long to build as a sailing ship does; ergo the sailing ship modeler doesn't buy kits as often. Imai, back in the late seventies and early eighties, gave us a hint of what ingenious design and financial daring could do with sailing ships. And Imai went out of business. That, presumably, was not a coincidence.
In the meantime, I continue to regard the old Revell Constitution and Cutty Sark kits as fine ones - even without taking account of their age. They're basically sound and accurate kits - far better bases for serious scale models than at least ninety percent of those high-priced, continental European, plank-on-bulkhead wood kits that are so often promoted as the "ultimate" ship models.