I think it depends on how much you use article marketing and how much are you making. Of course if you are making couple of thousands a month out of article marketing you will pay for the premium. I just started with article marketing and I was willing to buy premium membership but $97 a month is crazy since I am not making money out of my articles yet. What I do at the moment is just keep writing articles in Word everyday while I have articles pending for approval.
I'd say it's worth it just for the time it takes to get your articles approved. My last 2 articles being a Non-Premium member took them over 3 weeks. That's ridiculous if you ask me. I think article marketing has really put a lot of strain on EA's servers and that's why they're changing their business model. And $97 is only if you're paying month-to-month. If you're completely serious about your bum marketing you'd pay in advance for a year which comes out to be half of that (about $48) If you can get your article approved in under 25 minutes VS 2-3 weeks for $48 a month, it's a no-brainer...