I have an unlimited account, and I need to backup about 2TB. First I paid the $10 upgrade, which got me an upload speed of about 2.2Mb/sec which isn't bad, but I would have expected faster. My backup ran for about a month reliably, then just when I got to 1TB of storage, the backup program stopped and wouldn't upload any more files. I asked support, and they told me that my account had been suspended for using too much bandwidth, and wouldn't give me a timeframe for lifting the suspension. So I have unlimited storage, but I'm not allowed the bandwidth to actually use the storage.. So the unlimited storage option is actually 1TB only. Other that this annoyance, I actually liked the service .
I have been using JC for a while now, and so far I am pleased. I have used other services as well, but JustCloud seems cheaper and easier to use. And, the RESTORE of your files actually work! (I have tried services where this is NOT the case)
It should also be quite future proof since they are using Amazon for the cloud-stuff. Also very nice that you can use multiple devices to check your files and synch.
What I absolutely DO NOT like are all the "hidden" costs that you don't realize that you need, and you have to pay extra for. Eg. VideoFiles don't get updated automatically if you don't pay for it! (totally crazy!) Ohh, you want to back-up files larger than 5MB? Go to the settings and fix it! (Why???) You got NAS/external HD you want to back up? No problem...if you pay $$$ ! And so on....
And also I really don't like the annoying e-mails and pop-ups about buying this extra-stuff all the time...I almost wanted to quit using the service because of this. (found the "don't spam me button though")