Build quality is very good for both although the Solo is more premium and made from metal.
And while it is anatomical and comfortable for it's size the truth is that it can't touch the IE300.
The Sennheiser is so small that it vanishes inside the ear.
Discreet, super lightweight and very comfortable.
You will forget that you are wearing it.
Who wants that! I want people to see my beautiful sintered steel beauties with the nice black Lyre, touch is a little rough too cause at retail on the IE they are twice that $150 Solo sale price so one might expect them to sound a little better but then again it's all about your personal sound preference. I like the detail, clarity and brightness of the Solo's and they for sure are not even close to a bass monster but I find it solid, tight and fast No doubt both are nice iem's