Aw, it's too bad you didn't find the right solution. I did not like the gel pads with tights either -- they kept slipping and I felt like I was tugging them up constantly. I also wasted money on the sleeves, which feel like they would fit my elbows much better than my knees!
What I ended up doing was taking an Ace bandage (cheap, from the drugstore) and cutting it in half. I wrap it around the gel pad and use the fasteners they came with, and it stays put without adding much bulk. (I bought a pack of backup fasteners from Amazon too, just for this purpose. They do last a while though.) This has been working for me for over a year. If you ever decide you want to give them another try (or want a slimmer solution) maybe this will work for you.