Juro:
It sure sounds like you've done lots of experimenting and I'm intrigued by your suggestions. But also a little confused. What exactly are OS Systems, waders or a diving dry suit? If it's a dry suit, it must be very clingy, no? Also, most of my fishing is done not on sand beaches but on rocky, barnacled coast. How do soft (I assume) diving boots hold up and protect your feet in places like Squibnocket or Gloucester? Where are OS pruducts available?
I do agree with you 100% on wearing fleece under the waders. Happiest day of my life was when it occured to my to wear my light fleece ski pants instead of jeans under my waders. What a difference! I've heard some guys actually wear panty hose but I'm a bit too bashful for that.