Malfoy, I can't tell a difference between the various file types when I'm listening to them on my phone. I usually only listen to it when I'm at the gym, walking at the park, or just out and about, so the music competes with other noise anyway. Maybe you could save lossless files for when you're using quality headphones and speakers rather than earbuds and a phone. Play around with an online audio converter or mobile app to see if you can compress your MP3 files further.
Subjectively, I've always felt that vinyl produces the best sound and cassette tapes produce the worst. My tapes never lasted long and they didn't sound great to begin with. Then again, I played my favorite songs over and over while skipping the duds. I'm sure all that rewinding and fast-forwarding didn't help. Every Walkman I've owned has been a real pleasure though. I dropped them many times, but each model kept ticking along.