The license states "Can modify source-code but cannot distribute modifications (derivative works)". Seems to be really go against what open source is all about and I am curious on others opinions.
No. I really am happy that I have paid for it. Even with some other solutions out there that appeared to be a bit cheaper.
For $10 you get a significant amount of storage, don't have to run your own NAS (or shell out the capital expense of buying it), backup drive without redundancy, or pay any electric bill related to it. You also get very nice integrations into other platforms.