very good point. Have to add I run both Google Drive (larger box, 5gb for free, for personal stuff) and Drop for shared stuff never seen them "competing" in any way.
Another thought is that on personal Google account I only keep couple TrueCrypt containers, based on size and open read/write close them any time I need the access. This is necessary because once you unount TC container, entire file is affected so it needs to be shipped back to the cloud. I have couple 50MB ones, some 100MB and some 1GB ones. I know its not the convienent way to access your files, but I dont want Google (or drop box) to have open access to my files.