I use the free service and have about a hundred articles (expert I think, or is that platinum). Anyway unless it I submit it over the weekend it's usually live in about a day. Unless you really need the scheduling stick with the free account, after a few days it won't seem to matter as much if it gets accepted a day or two sooner. But if you want to try a time it so it sticks for a couple of hours on the front page then the premium account might be worth trying.
It's worth about as much as a $300 link on BOTW.org or Yahoo Directory. In other words, no Before anyone goes off on how it passes great PR, I want to interject and note that it's passing on a PR N/A or PR 0 link to your site. Hardly the kind of investment I'd spend $90+ on.
If the article gets spidered while on ezinearticle's homepage it will get a high PR link and it does boost the ranking in the SERP's. I've seen a number of articles hit Google's first page this way. Yeah okay it's only briefly until Google updates again, but if you do this numerous times with a high converting product or high Adsense CPC it can make it worthwhile. While doing keyword research I found a bunch of articles that were on the first page of Google yet were only published a few days earlier. These were high CPC keywords ($10-$18 dollars)that obviously was using that technique. But you have to schedule it just right. Normally articles stay on ezinearticle's homepage for about 10 minutes before it's refreshed with newer articles, and it may or may not get spidered, but premium accounts can schedule it so it stays on the homepage overnight (several hours) so that it's assured of getting spidered on a high PR page. But you have to be able to hit the "sweet spot" and do it with a number of articles to make it worth your while.
eZine used to be good. It sucks now. With that said, I wouldn't pay $97/mo. for what it used to be. I might pay $97/yr. but I would want a month for free. Very few services are worth this kind of monthly dough imo.