Watched Top Gear review on RX8 once. They loved it.
Jeremy Clarkson actually said it was one of the best car he has ever driven in 2003.

Performance wise, unless you track your car semi competitively, difference you will see it on everyday driving is minimal. Although, S2000 is quicker it lacks creature comforts that RX8 offers.

I like RX8's design alot. But as I am true to my passion I purchased S2000 at the end and I couldn't be happier.

But every time I see RX8, epscially dolphin gray color, I turn my head. With Mazda Speed body kit, RX8 looks stunning. But at the end, it boils down to this.

S2000, pure bred sports car.
RX8, Sproty car with 4 seats and all the amenities.

Make sure you evaluate main reason for buying the car. What is your objective here? Both are great cars although, I would say Honda wins in reliability department hands down.

 

I have an '02 S2000 and test drove the RX-8 as well, it is not the sports car the S2000 is, but for a daily driver it is one great car, very comfortable, yet refined.

My one issue with the Mazda is gas mileage, I have heard it is pretty terrible, anyone have any real experience with this???

 

They are both great cars IMO. PM MattH25 with questions.. He owned an 02 S2000, and now has an RX8. I've driven his car, and it is definitely not as quick as the S2000, but it's no slouch either. It's more quiet in the cabin, and has more features as well.

 

I test drove over 1,000,000 in total car value on my three month trek for a car. I wanted a roadster when I got all done and went with the S. If I wanted AWD I would have gone with the EVO and if I wante a middle ground sports car with lots of goodies it would have been the RX-8. I liked the room, the trunk space, the doors, and the navigation system. It all worked well and drove really nice. I however wanted auto-X capabilities and the S outhandled the top of the line RX-8 I drove and had more power. So in January I picked up my02. Good luck with the car options just pick what you want and like.