SugarSync

Of course, because they dropped library support:

Dyld Error Message:
Library not loaded: /usr/lib/libcurl.4.dylib
Referenced from: /Volumes/Install SugarSync 1/SugarSync.app/Contents/MacOS/SugarSync
Reason: Incompatible library version: SugarSync requires version 7.0.0 or later, but libcurl.4.dylib provides version 6.0.0

I had to spend 1 hour to find a version that still works v. 2.0.42 looking on web. They don't list old versions on their site but they are known to force you to update through the SugarSync app. So I am wondering how long this version still going to work. If they had a free plan, I wouldn't complain... e.g. I don't spend time point finger Microsoft doesn't support 10.6.8 with their OneDrive because Microsoft never did support it, but they do have a free plan. SugarSych just charges horrendous amount of money presenting themselves as a "business" solution but in reality support has been always poor from these guys. Software is well designed and it works, when it works, no issues, but if there are issues, you are on the hook, buy a new a computer instead. SugarSync is a sad story and an example of how to create bad publicity for a company that has virtually unlimited competition. It's a surprise they still exist, the only thing that keeps them afloat is the number of users who are reluctant to switch. But as the effect attrition starts to kick in by estimate it's a question of time how long this company can continue the current model.

Sorry for double posting, no way to edit my post once published. Latest release prior to version 3 is v. 2.0.46.

Today I got some really nasty experience with SugarSync. I have about 120 GB in account and I was uploading a 60GB folder. It literrally forever to upload, the upload speed was 2kbs. That's like nuts compared to what I get with Box.com where I have 50GB free as well or Mega storage. Even Google Drive throttles the upload if there are small files but nothing like SugarSync. After waiting forever the upload not finished after almost a day, I cancelled it. Bad mistake. It took maybe an hour for the app to be finished with whatever it was doing. So I decided to remove the synced folder. Wow. I almost lost my stuff. There is no way to actually remove the synced data without actually deleting the data from your disk. One option is to create a backup copy of the data I am going to remove from SS. Another option is to do it online, remove the data there and then wait for a few hours till SS gets all in sync again and cross fingers it's not actually going to delete the data locally (which I am afraid is the case).
After fighting with it for 4 hours, my system was slow like snail, without the SS app doing anything meaningful other than slowly purging the local index data, I decided to whipe the app clean and reinstall it.
Unfortunately this has been the worse experience with any synching app. Even though SpideOak which holds the crown as giving the most challenging times, Spideroak is at least very secure and reliable once it works. SugarSync has a nice interface and easy to use, but I am really left in disbelief about how this application handled large upload and subsequent cancellation of the upload and removing the data.