I can't feel my band, though I've heard a few people say they can.
I'm aware of my band when I get food stuck in it (in the stoma, actually - the small opening between the upper and lower stomach pouches). Then I feel major pain and pressure in the center of my chest. Occasionally I can feel food moving through my stoma - a weird sensation, but not painful. I don't feel the physical presence of this plastic ring in there.
I do feel my port sometimes when I bend at the waist, and I can palpate it by pressing on my abdomen near my port incision with my hand. It's a hard lump. I kind of like feeling it and knowing that it's there, ready to do its job.