My summary is the following. It is a summary of playing many games with the 'average' user of KaM, not the self-proclaimed 1337 that you find in certain locations.
The changes made in the RC had one effect, that nobody considered before: the improved gameplay tactics spilled over to r4179. So you find quite some players producing mass militia, some go for pikeman and some stay with lances. You just don't find axemen because usually people go for scouts then immeadiately. It totally depends on the map and on the players.
So the +1 def was a very nice idea to bring people to develop new tactics. But there is no need to implement it into the final release. Even if the balance is not considered perfect in this forum, you find so many tactics out there, that it's real fun to play nowadays. Keep it that way! Trash the changes.
So... you want to leave unit values from current version (r4179), because the "+1 defence against shooters" for shielded units is not needed? You really should play a few RC games... it's so much better. This change provided some much needed positive effects, like changing the default unit to a one which is harder to make, making horses very valuable again, also (but not exactly related) bowmen are really useful now, not just meat for xbows... Every single game something different happens, players keep changing strategies, and I really doubt that it's because of placebo effect (as you seem to suggest). The best thing is, it all really feels balanced, and all kinds of units are being used in every game. I think you're really missing the whole fun if you won't give the RC version a chance. Aside from the "1337 player" TS group, there's lots of new players in RC (usually Polish... Mixons' 1v1 Polish tournament was played on RC, so credits to him for making it more popular
), so it's not hard to find a game there nowadays.
About lancers/pikemen being left out - well, it's still better than it was before. In current version, the units left out were all kinds of shielded units (including horses, well they were more useful than axemen/swordmen but rare to see). Now, the units left out are scouts and lancers. It's still way better than it was. Pikemen are not exactly left out - even if everyone usually makes swordmen, pikemen are still useful, for example when:
-countering knights
-tactics like Pizza's, where you want as much bows as possible, so you don't have time for huge iron production
etc. I am of an opinion, that lance/pikemen are supposed to be a support unit, not the main force in the game, so I totally support the change.