Lets look at the quotes you guys provided:
"The Enterprise redesigned, increases Phaser power by channeling through the main engines. When the engines went into anti-matter imbalance, the Phasers were automatically cut off."
Wasn't there also some mention of the shields being upgraded, which is why they handled the 1st volley from V'ger? Also,
Yes, Sulu pointed out that the new screens held after V'Ger hit them.
All this says is that there were
improvements. Nothing that indicates doubling the number of phasers. Upgrading to Ph X could be justified by this. The Phaser power getting direct channeling from warp can also be considered a defect, the moment the engines had trouble they lose phaser ability.
The shields were upgraded, but nothing to say how much. It could be a 5% increase and still hold against an attack that would have broken the old shields.
Nothing there indicates a quantum jump in power instead of evolutionary changes.
In any case the major thing is the affect on the game. Once the X-Ships come out the game changes suddenly and dramatically and for some of us in a negative way. I myself LIKE the fact that ships have flaws and weaknesses, X-Ships remove those weaknesses and flaws.
As I recently said:
With our discussion of relative ability to take damage we actually expose one of the weaknesses of SFB. Later designed races took into account experience with the existing races and customized them to avoid weaknesses in older ship designs and their weapons were designed to take those weaknesses into account.
Consider the Hydrans. Strong center hull so they are protected the longest versus the 3 most common rolls. Their major enemy is the Klingon Empire and their major weapon is designed to hit the Klingons ships in their greatest weakness - the glass rear shields.
It is unfortunate that SFB didn't tell the designers "get stuffed with your super ships".