I've had the 215s, 535s, and UE6's.
In my opinion, the 215s were trash for anything beyond easy listening to Spotify and blocking out kids / dog noises.
The 535s were my first step into Iem's and I really liked them, and they are excellent for listening to music if you get the seal just right.
The UE6s though are miles above either of these, especially for live use. The bass is simply phenomenal, and it's probably subconscious, but they do give the illusion of "feeling" the kick and bass. Definitely worth stretching to / saving for those if that's a realistic option.
Good luck!