Well I know many 2s that are as heavy as an Apex and thats freaking heavy....LOL
Not much if any better environmentally than some of the newer 2s
My apex turns 11000 rpms easily - which 2s turn that?
Obviously we know of the great reliability of the Yamaha 4s, cant say the same for others so really dont want to comment on that.
Yes they love boost.....LOL