The KSC75 will scale with the device you are using. In other words, its volume will depend in large part on what you are using to generate the sound. It is actually very easy to drive, and most portable devices will work well with it.
I'm afraid I haven't heard the others that you have mentioned, but I know that the Sennheiser 201 isn't well regarded at Head-fi, at least not for music. For your purpose, I don't know.
Here is a current guide for headphones over at Head-fi: http://www.head-fi.org/a/headphone-buying-guide
Take a look through the budget category.