Vehicle rushes don't feel good.
Maps that have key vehicles available to be rushed can really suck. Paradise in particular stands out for this in my mind. Ship side starts with extra tickets, and a little bird. They can easily get to the apache first, and if smart, the anti-air as well, making it virtually impossible for land side to recover. That the apache and little bird can virtually outrun talon rockets, just leaves it too unbalanced.
I'd mind the helicopter rush less if both sides had a starting AA vehicle, at least then you can try and scare the apache away, even if it's tough to destroy.
I realise that you can still win with a good team, but if all things are equal, boat team get a massively stronger start.