We have the 17 vert, so it's even heavier. Ours has the 6 speed manual with 3.55 gears. We have no issues with our clutch or tranny so far. We also found it to be too quiet, so we added a full MRT exhaust system and it now has a wonderful sound.
Performance wise, I find the car to be very smooth with a wide power band. Ours launches nice and straight with no wheel hop and on the factory P-Zero's (which I don't like) I can repeatably click off 5.2 second 0-60 times. Handling wise, I find the car to be too isolated from the road for my liking, no matter what mode the car is in. My Mach feels more connected to the road. I don't like all the nanny controls and have found that you can't completely turn them off. Even with the traction control and stability control off, the car still won't allow a rolling burnout for more than about 2 seconds. It cuts the power to regain traction.
Because it's a convertible, we do have some body shimmy on rough roads. I added a set of jacking rails/subframe connectors which helped stiffen it up some. I'm considering adding a front cradle to stiffen it up even more.
It's a fun, smooth car to drive, but I don't yet trust it at its handling limits like I do the Mach. It seems more apt to suddenly swap ends with no warning.
We're keeping the Mach as well.