FWIW I really like the Indy 500 for a 3 season tire (I run them in the cooler months with RT615K+ on my NSX, along with RE71 and A052 on my S2000), they grip well even down to +5C weather (where the others turn into hockey pucks). My only gripe is that their sidewalls are softer than I like.
I have new 17/18 wheels that will need tires this spring. I'm leaning towards the Indy 500. I liked reading that you thought the Indy's were pretty good down to +5C weather (not that I'd probably ever drive in that temperature). What size wheel do you have your Indy's on? I ask in case your sidewall may be taller than mine due to wheel diameter.