I have been an online member for 20 months and it works perfectly for me, (did classes previously and I didn't like them) but........
There wil be success/failure stories for both options- what you have to do is decide what will work for you. Do you need the discipline of a public weigh-in, personal support, a tailored approach that you would get from a consultant, group support, etc or would you be happier with more generic support accessible any time, no personal interaction with anyone, weigh-in's that you can control the time of, not having to leave the house, etc
Good luck with your choice