With the exception of horrible visibility especially when backing up and changing lanes I loved my IS. At about 30 thousand miles I started to experience a shutter when coming to a stop intermittently. I had it in the shop twice for the problem and they told me there were no error codes and it may have been bad gas. My car is now at 61 thousand miles and needs the valve springs replaced. This is the same problem that there was a recall for on the IS350 and a few other Lexus models a few months ago. I think they need to add the 250 to that recall.
Cooled seats and body design.
Change the horn so it doesn't go off whenever you make a tight turn when parking.