Ability to support operating systems
In this respect, OneDrive is the best and iCloud Drive is the worst. It clearly shows the thought of Microsoft and Apple, Microsoft is always open to everyone, partly because OneDrive comes after Dropbox and Google Drive ( Skydrive precursor to Google Drive but not very successful ), so Microsoft must practice Middle promoting on every platform to attract users. Meanwhile, Apple only supports the necessary platforms and they focus on doing the best on it. iCloud Drive is deeply integrated into iOS 8 and Mac 10.10. Therefore, if you only use Apple symbiosis, iCloud is the most suitable and if you use all platforms ( except Windows Phone ), Dropbox, Google Drive or OneDrive all support well.
In case of using Windows Phone, you can still use Dropbox applications from 3rd party but it is not genuine and not as good as original Dropbox on other operating systems. At this time, OneDrive will be the more optimal option. Google Drive is hardly selected by Windows Phone users.
Using Android, you can freely use Dropbox, Google Drive or OneDrive. It is clear that Android does not optimize or integrate deeply any service, including Google's own Google Drive.
While operating system support is one thing, another thing is equally important: support within the application. Due to the earliest and most popular release, Dropbox is integrated by many developers into their application, you can access it directly without having to go back to the Dropbox app. This is especially important for closed operating systems like iOS or Windows Phone. Moreover, it is also much more convenient, for example, the application's own data will also be synchronized to the cloud continuously without concern.
Price list of cloud storage services, calculated on a step-by-step basis, not to accumulate free capacity.For example, if you pay $ 24 for Google Drive you will have 115GB and not 100GB and $ 120 is 1015GB.$ 100 for Dropbox is 121.5GB if there is 19.5GB for free and 2GB for free
Price is also very important point, if a service is too good but the price on the cloud is very few people can access it. Usually each manufacturer will give us an initial free capacity and give more if we invite users or activate certain features. Dropbox's maximum free capacity is 2 ( initial free ) + 16 ( invite more friends ) + 3 ( camera upload ) + 0.5 ( get started, twiter, FB ) = 21.5GB. Google Drive does not invite you but offers 15GB, OneDrive is 15GB after inviting and activating the upload camera and iCloud is 5GB. If you sign up to use Office 365, you will be awarded 20GB OneDrive for each account (up to 5 accounts) .
In the case of payment, iCloud Drive has a big advantage because it has a $ 1 monthly package, just a cup of coffee. This is an extremely acceptable price.
If you pass the level of 1 USD, you will see Google Drive has an advantage because you only have to pay 24 USD to get 100GB while this amount only brings 50GB on OneDrive. Dropbox is worse when it requires 100 USD to get 100GB of storage. Quite strangely, the famous Apple exorbitant price is very reasonable: $ 48 for 200GB per year, as cheap as 1/4 Dropbox. In case you want to save large capacity, you only have one option: Google Drive.
This is a more personal feeling than accurate measurement of science because every time there will be differences depending on the network speed and where you are. I found Google Drive, iCloud and OneDrive or Box.net are very fast compared to Dropbox when used in Vietnam because the above services have servers in our country or located in Singapore with huge traffic to Vietnam. In the US and Europe, it is unclear, once Dropbox is the most stable and there are times when Google Drive is the most powerful. I tried 2MB / s when transferring Dropbox in the US and 800KB / s with Box.net in Vietnam.
Another note: depending on the same name, firms will prioritize which services they feel more important. For example, if you restore your device from iCloud, it will be very slow, but download the app from the iTunes Store sometimes to 4-5MBps at the same time in Vietnam because Apple prioritizes this channel.