I purchase both.
For sentiments, I purchase wood--particularly any set with SMALL sentiments. Small and blocks just don't work as well as wood mount for me.
I purchase mostly clear on other things because I have very little space. However, I do not use their image stickers on the back. I really think SU needs to rethink those stickers. They simply do not work.
Cling from other places, not a problem. I have no trouble with other companies' cling--just SU's.