This is likely one of those circumstances where the phrase "you just can't please everyone" fits to a T.
My biggest gripe if you will, with multiple systems with different "guidelines" for ship building, along with different rules sets for handling a given conflict between ships - is that they tend to be mutually exclusive of each other. Prior to TNE, ships didn't have to contend with the issue of running out of reaction mass for propulsion - and consequently, battles between those two genres were going to by its very nature, be different. Making something compatable across the spectrum for ALL ships would have required that ALL ship building systems adhere to the very basics of the original ship design rules. Case in point - the use of a given amount of fuel for jumps changed between CT High Guard rules and that of MegaTraveller rules. I dislike INTERSTELLAR WARS precisely because it permits ship designs that were illegal in the first version of GURPS TRAVELLER.
Now for the fun part...
When you base your traveller universe on quasi-historical events that had preceded the "current" events - a little bit of care should be taken to insure that the ship design and combat system produces results that are comparable to the original events possible from the earlier design system. Put another way? Imagine designing a set of rules, where the American Civil war is fought in a particular fashion with Rules set A, then designing rules set B such that the events from rules set A are retained - yet are NOT possible using rules set B? The "disconnect" becomes all the more pronounced when someone tries to go back to the original "events" and finds that it is not possible using the new rules.
One thing I discovered the hard way, back in the day before I settled down on a specific set of role playing rules, is that when you utilize a given role playing system, and want to continue playing in the same game world you started off with - translating characters from System A to System B is never 100% perfect. So certain abilities present in system A are what you stive to recreate, but the "extra abilities" present in system B become lumped in with the abilities from System A. Then, God forbid that you want to translate to system C, because now you have legacy issues with both A & B, and system C almost always adds new abilities to be used by the character. This happened to me when I utilized TFT, went to DragonQuest, then to Rolemaster, and finally, went back to TFT for my campaign world. The character which had been translated so many times in those differing systems, became an UBER-Diety by the time I went back to the original system.
Likewise? I disliked the ship building rules for MgT because of the very thing that is now seemingly to become standard with T5. New ships will outgun old ship design philosophies - rendering any continuity between older versions of Traveller history a moot point. Ironically, the VERY same issue arose with GURPS TRAVELLER. There, missile weapons became Ship Killers in a major way as an outgrowth of GURPS VEHICLES rules, which were NOT the same as High Guard rules. Translating ships specifically from the older Traveller rules set into the newer GURPS TRAVELLER rules became an exercise in futility - because the weapon systems and rules had changed dramatically.
Ah well. So be it. Trying to utilize the Fighting Ships from CT and T20 is an exercise in futility. Trying to create the "signature ships" between systems becomes an exercise in futility because the way a given ship worked in its native system, will no longer be valid in the new system.
THIS is why I am not happy with T5 or MgT's wave of the future. But, that's just me
