"Some owners have reported premature wear or even ripping and tearing of the leather seats, and in particular the driver’s seat."
This is a common problem on G35s as well. The leather on these Infinitis looks better than it actually is. The battery draining issue is also common on G35s and stems from a small compartment near the passenger firewall that can't house a larger battery, which would help with all the electronics on board. Likely it's the same setup on the EX.
Despite that, these vehicles still represent an excellent value and I would choose one in a heartbeat over it's German competition for reliability and servicing costs.