I listened to Think Demo and while it had some nice ideas, I think you could really benefit from purchasing some different string libraries. Also when the strings join in with the solo cello, they're very much in the background. While I like this approach at first, I feel they show grow into a better balance with the cello. Like the cello has the lead at first and then the whole ensemble is working together and presenting the musical ideas.

Also things sound quite dry.

Sad demo has a great opening motif and mood. Very cool! I liked this one quite a bit. Some of the same issues happen in this piece as with Think Demo. Compositionally, there are some very nice things happening here! Production-wise there could be a bit more work done.

I think part of the challenge is figuring out what kind(s) of projects your music will best support.