As someone who has recently sold a Porsche and who will be buying a Maser at some stage my assessment is as follows.
. The Caymen is more of a drivers car (it's smaller and lighter, it's a proper sports car, more agile, and has option of a proper manual gearbox) and costs way less to run. Something you will jump into every time, enjoy, and not worry about.
. The Maser has soul that no German car can replicate. It will make your hairs stand on end. You have to own a pedigree Italian car to understand this. It's so much more than well designed and put together bits of steel. I remember many years ago test driving a new 350Z and thinking this is nice. Then got back in my Alfa GTV, listened to the glorious V6 (yes the engine rather than the Zs computer tuned exhaust), pulled away and soon apologised to her for even considering the change.
. The caymen is a "head" purchase, the Maser from the heart.
. The Maser is a dumbed down Ferrari, but from reading all the issues raised on this forum appears to have full fat Ferrari running costs.
. Most on here say MC Shift the way to go, which I'm still struggling with as GTS is a very big heavy car and thus a GT which to my mind an auto box is better suited. But I haven't tried an MC Shift yet and the auto I test drove, even with the Sport pack and quicker shifts, still felt a little remote.
. Red trim, esp. inc. stg wheel, is love or hate and, as Mr Grace says, is probably why that car has been for sale for a very long while. Give it a miss unless you intend keeping car long term, in which case it might be a good buy.