I know this sound generic but "I love my car!" this was my first new car and it is still my daily driver. I currently have 88,090 miles and I am still running on the original front brakes, clutch, belts & shocks! Driving stick really extends the life of your car. Only had to replace 1 bad shock, the battery, rear brakes and everything else is from 2004. About to change the timing belt, water pump, etc. but I'm almost at 90,000 miles so my is 300 has done me proud. You expect quality and reliability from Lexus/Toyota and they delivered. Mine is is so much fun to drive, it's quick around corners and the ride is very smooth. The transmission is the smoothest I have ever driven.
I love the smooth 5 speed transmission. The quick response between gears and the reaction time. I can easily down shift and overtake any car when needed.The durability & reliability are also great piece of mind. There are times i get behind the wheel and it's like the first time i drove her home.
Trunk space could be bigger and the rear seat is good for your back pack or a Child, not an adult. The gas mileage is not the best. My Land Rover LR3 is a gas hog and my IS is not far behind. My Mercedes C300 can go 240 miles and use less than half a tank. Rear folding seats would be nice too.