Hi,I wear and I also do Kenpo Karate.As was mentioned previously good attachment is the key.As each person's body chemistry reacts differently to particular glues and tapes it can be hit and miss until you find the right product that suits you.For Karate I wear a fairly short style so its harder...
I've brought a couple of systems from ebay and to be honest they were ok and in some cases better than units I got from the so called well established companies.As regards Easypiece or Hair direct I can't comment as I've never tried their units.There are alot of sharks in this business so...