In my opinion, its extreme speed is very useful (duh) but its very high shift time and requiring you to nearly freeze to turn is pretty bad. However, that being said, I find its generally quick enough to blow past the competition in time for the handling to not be much of an issue. But that's just me. I've been hoping to try out a Zonda, I just need a lil' more credits. I have 300k.
But I digress... By far, the biggest shortcoming is the shift time. Pretty cruddy there. One this that's really refreshing is to drive the CIEN, and then switch to the Mitsubishi CZ-3 Tarmac, which has pretty epic handling and shifts like there's no tomorrow.