Sync multiple macs together (which is better iCloud, Dropbox, Google Drive or OneDrive?) I have 3 MacBooks and I made a Time Machine on one of them e.g macA and then restore it on the others macB and macC. Now I want to keep the 3 Macs in sync where if I did some changes on any mac (added files, deleted apps,...) then it will be reflected on the other two.
I have checked and there are many options like iCloud, Dropbox, Google drive or OneDrive. and I read some links but it’s confusing to have a summary of the pros and cons of each one and which one is the best, so it will be appreciated to know from experience of people here what they think is the best option? since it will be good to have some advice to try avoid choosing one and having to switch to another later on.

I've been looking into this and I was testing how iCloud sharing works and found out that if I shared a folder to anyone with read only access they still have to create an iCloud account which is very inconvenient since many people who are not Mac/iPhone users don't have one. But also the good thing with iCloud is that I have an iPhone and backing it up with iCloud is a convenience. So I am really confused with which option to go with could people please advise me with what they think is best from their experience? 

I want to know the best option for me if this is what I am looking for:


Easy smooth syncing of folders across my Macs (Documents, Desktop, Photos,...)
Share files and folders with other people without the need of them to create a new account on the cloud platform so they can just download it, which I think is not possible with iCloud.
I can backup my iPhone to the cloud as well (with iCloud it can be easily done), but it's not mandatory.
The are all laptops so they are not on the same network so I guess a cloud based solution is best
The sync is done instantly so that I don't have to start it every time I open one of the laptops.
iCloud is better since you can get support from Apple. It’s also better since you can enable local content caching which speeds things up 10x or much more for some cases. 

OneDrive is getting better, so I would explore that if you like Microsoft.  

No cloud sync is going to make everyone happy or not have issues or barf and choke. But I choose based on who I want to hire for support and what happens when their support fails me, which I will then have to learn or pay someone third party for help.