I said zero difference in construction between GNU and Lib-Tech in general (after you indicated a potential concern about GNU construction/preference for Lib-Tech), not specific to the RC and/or TRS.
Anyway, asymmetrical sidecut and sintered are not really construction issues, but board features. The fact that the RC has these features is exactly the reason that I described it as an upgraded TRS (which does not have them).
Asym is a personal choice IMO. The theory behind the concept seems sound, but in practice some people see more of a benefit than others. For me personally it did not make much of a difference - in fact, I almost preferred riding the board the 'wrong way' around. There might be a learning curve as well
Frankly, the base makes no discernible difference. The extruded vs. sintered argument is an oversimplification - a high-end extruded base (like on the Lib-Tech boards) can easily be superior to a cheap sintered one.
As I said above, base should not really be a factor and asym is a question of personal preference, so there is no 'objectively' superior board among these.
Personally, I like the RC (the previous version without pickle/asym, though) but the TRS also has a very loyal following. These decks are quite similar in the way they ride, so you would not go wrong with either one.
The AB is slightly different (in the way that I described in a previous post). The general market reception has not been as favorable as for the RC and TRS, but some people really like it. Personally I rate it below the RC and TRS in general, but for certain situations (e.g., frequent pow) it might indeed be the better board.