My original DX starter set (from ebay) included a Roc. It was my first mid. Used it for a couple years.
Added a DX Stingray next. It replaced the flippy/beat Rocs as it was more consistent for me. Then as it wore in, and as I was getting better, it became very useful because of the crazy flippiness.
Needed a a stable mid and added a Star San Marino Roc. I liked and, and bagged it for a couple years, but I never felt too strongly about it.
During the SM Roc era, I also tried an ESP Buzzz. It immediately made the bag, being the "more stable" and consistent disc that I was looking for. It eventually totally replaced the Roc in my bag.
As my game improved I realized that I needed an overtable mid. Enter the Wasp and Hornet. I have a couple Ace Race Hornets and didn't throw them after the race for some reason. I was looking for an overstable mid and got the Wasp. Liked it, but didn't love it. Then I realized I should throw the Hornet again and it's never left my bag since.
Finally, the Star Stingray entered my life. This is the disc that is my go to mid. Super straight for me. If I really torque it, or put a little anny on it, it turns right gently. And If I put it on a hyzer and throw it hard, it will flip up and fly straight beautifully.
So today, and for the last year and a half or more...
(2) DX Stingrays in worn and ultra worn condition for flipping and flopping!
(1) Star Stingray, my workhorse mid.
(1) ESP Buzzz for slightly more stable duties & some forehand escape shots.
(1) ESP Hornet for overstable BH and forehand duties.
Probably TMI, but that's my mid story.