Isoacoustics' Gaia eliminated a 120Hz mode

I read somewhere that with a correctly set up Gaia (logo facing the front or rear), the speakers can sway slightly from side to side but stay firm on the other axis without any movement at all. As for leveling, agreed that it doesn’t make much sense since speakers are heavier at the front due to mounted drivers. The other points you brought up are valid.

Nevertheless, I presume that the Gaias need to be loaded evenly for them to work properly. The loads from the speaker need to distribute evenly to all 4 supporting Gaias. Otherwise it will just defeat the purpose. An exaggeration to illustrate my point, imagine one end of the speaker at the base is hanging loose in the air while the other 3 footers are taking most of the load. The sound will not be good. This is the reason I messed up during the first time I installed the Gaias.

It is easier to set up the Gaias if your floor is completely leveled. In my case, the floor is slightly uneven so I will need to adjust the leveling to ensure that all 4 footers are evenly loaded if not perfectly loaded. I understand that perfect accuracy is not possible due to the aforementioned reasons. Nonetheless we can still set up the Gaias to achieve the best possible result with some effort. My speakers are sloped at the top so I can’t control the level at the top of the speaker. The control was at the top of speaker stand in my case with the use of a spirit level.

Another point is the Gaias have rated capacities to cater for different loadings. This just shows the importance of loading them correctly. They will fall out of the performance envelope if not properly loaded. I presume it is better to have a higher rated capacity Gaia support a lighter load rather than the other way round.

The manufacture recommends going bigger as well. This supports the notion that there is a range of effectiveness and that minor adjustments may yield a questionable return. Perhaps someone can tune it but I have neither the patience nor the butt to do that. 
I do agree that each corner should have the same give or wobble when pushed, indicating each is pulling (supporting) its share of the weight. I did have to do some adjustments on one of the mains as it was apparent that one corner was clearly shorter than the others with initial give before resistance. I think relatively level, symmetric movement fore and aft and logos facing front/rear is what I am going for.