If one were to pick one of the 2020 IEMs under $150 to stick with for a long period of time, what would you choose? I'm thinking the TRI Starsea might be a good, versatile pick?
How does it compare to a moondrop SSR/SSP?
I think @redguardsoldier summarized things nicely and I agree 100%.
Just to add on, in general it's comparing apples to oranges to compare single DD types like the SSR versus multi driver/hybrids like the Starsea as the different transducers have their strengths and weaknesses. Not to mention these sets are in different price brackets too.
Anyway in terms of versatility the Starsea wins due to the tuning switches giving in 4 sound signatures from V shaped to U shaped to neutralish. Starsea has better technical performance as expected of a multi driver setup but the timbre for acoustic instruments is a tinge artificial in the higher frequencies handled by the BA drivers compared to the SSR.
SSR has actually very good technicalities for a budget single DD and good timbre too, but it still loses to the Starsea in technical performance.
Starsea also is easier to drive but is picky with sources due to the very low 9ish impedance. It sounds good with sources with as low output impedance as possible (< 1 ohm ideally).
I haven't tried SSP but SSR is very volume dependent (fletcher munson curve). Sounds great at low volumes but on pumping up the volume the 3 khz area is an icepick for me.