[sneaglebob]

Like ultimate ears 11 pro and so on, which look like they are made of plastic and no visible foam or silicon tips makes me think that they are painful to wear. so are they comfy and are they really completely made out of hard plastic?

 

[UniqueMelodyAus]

Completely comfortable if you have a good fit and your builder has crafted them well.

 

[DrWebster]

If you're worried about completely custom IEMs being uncomfortable, one solution would be to buy universal IEMs and get custom molds made for them (from Sensaphonics or similar). Usually the custom molds will be silicone, and you have the added benefit of being able to get new molds made if yours ever stop fitting properly (such as if you lose/gain weight) without having to replace the whole IEM.

 

[alphaphoenix]

Most is made of some type of acrylic material, but there are more expensive all silicon build.  Westone elite series has vinyl tips for enhanced comfort, so I heard.  It's already mentioned that proper fit is everything when it comes to comfort.  Most places has 30-90 day fit warranty to do take advantage of that service even though it may mean another 1-3 weeks out of not having them. 
 
If you want to get an ideal of the process, fit, and comfort, the cheapest route it to reshell a univeral BA IEM.  That way, if you later find out that it's not ideal or what you're after, you'll take a much less hit on the resale value if you decide to sell and move on.

 

[ori88]

Much more comfortable than IEMs jammed into your ear canal since they don't sit as deep.