Those are the kind I use. They try to be flat but there's really nothing you can do to stop concert level bass from getting through, so they end up being a bit boomy. I've found that I can move them in or out of the ear to adjust the dampening. If they are in too far I tend to not like the way it sounds. I like it at the most minimal dampening I can get. It sounds good and it still keeps me from getting concert-ear.
Also I've noticed that I can hear the music much better with them in (when it's too loud I have a hard time distinguishing pitches—singers often sound like the Chipmunks) and some groups don't fare well when you turn down the volume a bit (they use volume to mask lack of ability).
I use the happyears: http://www.happyears.co/
I recommend them, they're cheap, easy to clean and quite comfortable.
Sound quality is always harder to tell (and subjective, it's hard to own hardware to measure it), however they're fine if you ask me. I own pairs of ER-20 XS and pluggerz music, and the happyears are my favorite (pluggerz is quite good as well, happyears are slightly more difficult to fit in the right place. ER-20XS are just uncomfortable in my ears).
I use the Alpine [1], and I use them to protect my ears from the screaming of my toddler. They cost 13 EUR, custom-made cost around 150 EUR. Custom-made can be worth it if you use them a lot, and if your ears are non-standard might be downright mandatory.
But I've been using them too late because recently I have tinnitus in the evening before I go to sleep (I do wear the plug at night as well). Am in mid 30s.
That said, clubs/shows play music way too loud, and I occasionally hear the beginning of tinnitus, so I 100% agree that people should get a pair.