OP asked for something a "little bit similar to them, but better sound in some way".
The Piston 2 is v-shaped and warm, but I felt like it had boomy enhanced bass. The soundstage was good (from the large vent on the back). Clarity and imaging weren't bad either. The treble was bright and sparkly, and had a smoothness that was enjoyable to listen to.
The reason I mentioned the ones I did, is I think they bring to the table the basic essence of what the OP enjoys about the Piston 2, but with some enhanced property/properties.
Xiaomi Pro HD: I think the Pro HD is great for the genres the OP listed due to its U-shape. Nice clear mids, deep punchy bass, and bright sparkly treble with lots of detail. The soundstage of the Piston 2 edges out the Pro HD though. The OP will feel right at home with the typical excellent Xiaomi build quality, fit, & finish. And if the OP wants even more sub-bass/bass, the front vent can be closed off with tape of glue. With that modification done, I think it outshines the Piston 2 from an overall perspective.
ZST: While the ZST doesn't have enhanced bass, but there's plenty of sub-bass and bass that should please the OP (although not as much as the Piston 2). The ZST has better clarity than the Piston 2, and the detail is every bit as good. Like the Pro HD, the soundstage isn't as good as the Piston 2. The ZST definitely has brighter treble compared to the Piston 2. Rock and Rap sound great on the ZST.
ZS5: Again, another U-shaped sound which I like with the genres the OP listed. The clarity, soundstage, and imaging of the ZS5 is superior to the Piston 2. While the treble is the brightest of the bunch, it pairs well with the overall sound and isn't peaky or piercing. The bass and sub-bass is plenty for Rock and Rap, and like the Pro HD if the OP wants a significant bump in bass the front vent can be closed off with tape or glue (that's what I did to mine). With that modification done, the ZS5 is like the Piston 2 on steroids.
While I didn't listen to the Piston 2 for years like you, I did spend about 3 weeks with them when I was deciding between them and the Xiaomi Pro HD. I definitely enjoyed them, and Xiaomi makes great IEMs. But ultimately I liked the Pro HD better.
I should also point out that I used silicone tips on all the above. No foams.
Obviously these are my opinions. You may agree, you may disagree. It's your prerogative.