The Conti Extreme Contact Sport is a better match to compare to the 500s. That's what I have now and they are great, but I don't have a way to compare to the 500s. I think the 500s are a bit less money, but you can find deals on the Contis as well.
Edit: I incorrectly thought the 500s were a Max Summer Tire, not a UHP Summer Tire, minor difference and same tread wear all around, but my recommendation for the Conti ECS is still the same. If you don't deal with a lot of weather the ECS's should be a bit more aggressive.
I have the Conti ECS and the Indy 500's in my driveway and have driven both on street and on track days. On the street they're both excellent although the Conti's sidewalls are a little softer and more willing to soak up small road imperfections. The Indy 500's definitely feel like a harder compound and therefore transfer more NVH into the cabin in comparison.
The turn-in on the Indy 500's is razor-sharp, and they're pretty even with the ECS in the rain with regards to grip and hydroplaning resistance. Both tires have excellent response. The Indy 500's are slightly louder at cruising speeds.
However, on track the ECS starts to pull away from the Firestone pretty dramatically. The Indy 500's dry grip is predictable and comes with excellent initial response which makes setting your slip angle into turns very easy, but compared to the ECS the overall mechanical grip is a noticeable level down. The ECS has the
slightest delay in initial steering response, but once it bites it sticks almost like an extreme performance tire. Those coming from a Michelin PSS know what I'm talking about. Same thing here.
The ECS was also a bit more linear when pushed past its limit than the Indy 500. Both tires are excellent in that regard. The ECS also had a bigger temperature sweet-spot than the Indy 500's and could be pushed to the limit of grip for longer without getting overheated and greasy feeling. Although the Indy 500 is an excellent tire (especially for the money), the ECS just feels at home on circuit in comparison. The Indy 500's are an excellent street tire that can be a great intro for track days / auto x. IMO at the novice level or above you're going to want more ...
YMMV.