Have been to both and more! Couldn't stick at either and gave up.
Personally, I think, now that the "diet" has to be for life and is more of a new eating regime, that going to diet classes and paying money every week doesn't work for me and is a waste of time.
I am now sticking to a lowish carb diet and have lost nearly 2 stone since September. We have a weigh-in thread which spurs me on too. And the low carb takes care of BG levels which is more important.
As soon as I think I am on a "diet" then I give up. A new eating regime is, phsychologically, much better for me and is working so far.