Very true, however the lurkers in all forums are trying to match the subjective opinions and explanations with objective graphs & stats if they are buying blind.
My iem history is short (in terms of quantity of products) but the progression to my preferred signature. The oldest is going from poor memory but listing the reason to get something new:
Bundled iPhone 3 earbuds - hurt my ears, didn't fit well.
Sennheiser ie7 - overwhelming bass, muddy sound. Ended up using for exercise.
Atomic Floyd (hidefdrum?) - sound leakage, sibilant. (No isolation)
Vsonic Gr07 - nice clarity, but fatiguing highs and sibilant. Despite rotating nozzle, it wasn't the best seal/fit. Somewhat underwhelming bass.
Shure se215 - soft sound with flabby bass, great isolation and fit. EQ bass down helped. Still use for gym as sealed DD design and hasn't been ruined by sweat.
Phonak pfe112 - neutral sound without peaky highs, really enjoyed these with grey filters however did miss some bass sometimes. Best fit ever. Lost them unfortunately.
Ultimate ears UE900 - gives some bass but still neutral without sibilance. This was my go to for a long time. Isolation was good for public transport.
Westone w30 - from reading criticism of ue900 I wanted to venture into something more 'exciting'. These had nice added bass texture but was about disappointed with a worse sound stage and I would consider less refined.
Westone w60 - after generally liking the w30 but felt there was something missing, a gamble on the big brother. It paid off. Nice soundstage, similar tonality with more refinement and a sense of clarity. Felt like a more dynamic and upgrade to UE900 and still fit like a dream.
Ibasso it00 - upgrade gym pair from se215 as was tired of the dark, muddy sound. Better in that regard, unfortunately has driver flex and still on the safe side with treble. Vent holes facing inwards is great because no wind noise when Running etc.
Fiio FH3 - chifi and hype train enticed me to try something with a more forward upper mids that is quite popular but without straying from what I was used to. These are really good however vocals can seem shouty (too forward in lower treble) at higher volumes. Isolation is worse than all BA so higher volume needed on public transport. Decided the Harman/typical pinna gain is not for me. I still consider it a nice natural tuning though but not as lush and relaxed as w60.
Sony Ier-m9: saw a good deal (living in Aus) and some homework seemed like the tonality of these spit the difference of w60 and fiio fh3. Really fits the bill for me, giving a more forward mid range, bit more excitement, great isolation but fatigue free.
The shell shape and size sometimes gives outer ear discomfort while other times it feels fine. So trying to pay attention to this at the moment.
Pretty happy ending on the m9 and feels like it meets my preferences to stop the upgrade-itis.
The problem now is that I have all these iem's, still like some of them and unlikely to sell them but at the same time trying to figure out when to use the other pairs!
Do people have their favourite but still switch between sets?
Is it liberating to sell them all off and get the best value from the favourites?
At the moment it's
m9 for daily use (public transport to work)
It00 - exercise
Fh3 - work from home use (lower volumes at desk)
W60 - comfort, lounging/lying around
Ue900 - look at for memory sake.