I don't use cloud storage, there are too many players now that are trying to establish themselves in the market. Many will disappear within a couple of years and any data will likely go lost. For the big players, I would never in my life use for example Apple's offering for obvious reasons.
When it comes to choosing something I also depends on what your needs are. Is it primary strategic storage for your business or also important for your hobby pictures, or is it a sharing solution you are looking for?
With many of us hobbyists needing +1TB and pros needing plenty more than that I have yet to see an offering matching those needs for a reasonable amount of money.
Make sure you have two back ups of your data, geographically dispersed. Manual back up is ok, you can do it on weekly or monthly basis. I agree with Mt Spokane also. It might not be a bad idea to keep it from being online.
I can definitely understand why you would not want to trust the cloud storage companies, but amazon or google are two that I cannot see going under. Amazon owns so much server space that when people were upset over amazon kicking wikileaks off of their servers, hackers attempted a DDoS attack which did not even slow down their website. This same attack crashed paypal, mastercard, etc.
Sorry, my point wasn't that Apple would go under. I wasn't clear, I just don't trust Apple, Facebook or similar with that kind of data. Look what happened to Instagram, there is nothing to say that other companies wouldn't do the same thing. Also, they are likely not targeting professional photographers with several TB of data, more likely people with tens of GBs. I just ran a back up of my January photos and it was closer to 30GB and I'm only a hobbyist. I expect to produce 6-700 GB worth of photos this year.
So not only about risk of the company going under but also the risk that they would simply take my data and use it for their own needs.