+1 for LX>Nio.
In general, the hybrid basshead IEMs in sub $2.2k range is loaded. I'd choose the following if:
-Nio: prefer lusher, warmer and darker signature without much treble extension. Some variability in bass control with the modules, but more of a fun, dirtier bass
-LX: king of subwoofer bass with incredible technicalities, especially soundstage width. excellent lower-midrange texture, lush mids, and laid-back but extended treble
-LXSE: strong bass response with a preference for a brighter signature focused around upper-mids and lower treble bite, while retaining top-tier bass response.
-Aure Elixir: W-shaped signature knocking on LX's door for overall technicalities, with better speed and control in bass region, although not as visceral as LX (nor is anything really lol). More focused on upper mids although mids and treble are pretty linear overall. Similar'ish to LXSE.
-Trio: U/V-shaped signature with excellent balance of mid and subbass, with a bit of bite up top. (I had the least experience here so I am sure others can clarify).
-Z1R: U-shaped with fast, addicting subbass decay. Don't mind a relatively laid back midbass response and slightly recessed lower midrange. One of the more fun trebles out there, although not necessarily the smoothest.