I have several of these discs in Strata, Cosmic, and Atomic and they all feel great and, being RPM, are some of the prettiest discs on the planet!
Strata - This is RPM's Baseline plastic, but I would argue that it feels like a Mid-Grade plastic and breaks in slower than a standard Baseline plastic. Naturally, this makes the disc slightly more understable than the Premium plastics. With that being said, This one is a bit more touchy on the shot in the wind. If thrown hard and flat it will turn and then have a slightly straighter finish. If thrown with hyzer, it will flip up to flat, turn slightly, and then have a touch more finish than when thrown flat. When thrown with anhyzer, this will hold the line for a while and then fight back to that straighter to low fade finish. In a headwind, these change a bit. Flat will turn quite a bit more and then struggle to fight back, hyzer will fly more like the no-wind flat release, and anhyzer will hold that line for days or turn and dump. I would say that this is 13, 5, -2.5, 2 for flight rating. I should also note that Forehand angles matter a LOT with this plastic and if you tend to majorly anhyzer your forehands, get this disc in one of RPM's Premium Plastics because this will not handle that type of forehand well, but if you have a great forehand WITH good angle control this disc in this plastic will serve you just fine.
Cosmic - This is one of RPM's Premium plastics, equivalent to Discraft Z or Innova Champion and many of RPM's have the Metallic Flakes making them super pretty and sparkly and looking more like the Innova Metal Flake. This plastic flies true to the flight numbers listed on RPM's website of 13, 5, -1, 2. Thrown flat (with power) it will turn, hold that line for a bit before coming back with a nice reliable fade. When thrown on slight hyzer it will flip up to flat, ride and then fade out. When thrown on anhyzer it will hold that line and continue to turn before coming back with that reliable fade (and provide a really pretty S-Line). In a headwind, it really doesn't change, except for the amount of turn you will get from the disc, with anhyzer being the only real difference as it will hold the line for days and fight back to only really a straighter finish and not much fade, but will resist dumping over. It also has the torque resistance for pretty much any forehand shot.
Atomic - This is the other Premium plastic of RPM and WOW does it feel AMAZING in the hand!!! Atomic is probably my favorite RPM plastic because of how it feels and looks and is just SO grippy and SO durable! Flight Numbers for Atomic are the same as Cosmic and the results are the same in the wind, so see the Cosmic review just above this.