My experience with these guys has been pretty awful.
I paid for their service two months ago. Since then it's managed to upload approx 10,000 of my 90,000+ files. I've spent numerous hours reading their FAQ, watching videos, tweaking my computer parameters, etc and it's been massively frustrating and mostly a waste of time.
They offer iDrive Express service, where you load your data onto a hard drive, but the postage charge for this - if you're in Europe, as I am - is $40+ ONE WAY, so we're looking at 80 bucks postage alone, and, based on the rubbish service I've received so far, it didn't seem wise to throw more money away.
I've chatted with customer service many times and at the end they'll assure me, "No, everything's fine now, it'll all sync no problem". I go to bed and when I check the next morning nothing's changed. When the sync eventually starts working, it operates at speeds so slow that it'll take about 6 more weeks, operating 24/7, for less than 400gb to upload.
Avoid this terrible service.