Performances are dependent on your system, some sceneries performs better on better system usually the newest ones. And, of course, it's wrong to compare very different size airports so, for example, saying that PHKO (Kona) has an higher fps than KLAX, doesn't tell much...
In any case, the whole point of having all sceneries available in Trial version, is that you can check their performances on YOUR system with YOUR setting and YOUR combination of other addons.
So, simply download, install them, and make you own opinion...
