Mans are not cheap too maintain... I did some research earlier this year while helping an owner in the purchase process and maintenance /parts can be much higher than Cats.
I think it's no secret that these boats are not designed for rough seas, if this is important to you, make sure you'll be happy with the handling. obviously, it depends on what you mean by rough seas and how you will use the boat.
SRs have typically crowded engine rooms, make sure that model doens't and that everything is accessible.