I also like trackballs although I prefer Logitech's trackman thumb trackball.

I also gave the Kensinton Expert a try but I really disliked it. For one I think I just prefer thumb trackballs, but beyond that I found the build quality really shoddy for that price. In particular the scroll ring is wobbly and rattles quite a lot on my model, it feels very cheap and is unpleasant to use.

You should have returned it. I haven't had that experience with mine at all

i really love the elecom huge, due to the fact that it has a lot of customizable buttons. the only downside is the scroll wheel that is not the best in the business and the position is unconfortable at first. but the trackballs for a long period usage are far superior in my opinion