The most important thing I can write here is that this is not a conventional low cost microstock site. A lot of people complain that they get no sales from this site, but it caters for a different market, I don't think the buyers are amateur designers who want a picture of an apple for their health blog.
As photographer you set the price of your image between 20 and 300 dollars, and gain 70% of sales, this is similar to sites like alamy, but sales are slow (in fact they are pretty much 0). Its hard to be fair reviewing this site against the microstock sites here because the customer is likely to be in the higher end of the image market, regardless of that if there are no sales then its a waste of time.
The whole thing leaves me wondering about what has happened to the traditional high end royalty free market, and if your hard to find exclusive images would not be better served being distributed as rights managed I from what I can tell that market I still very much alive.
I can't recommend imagevortex as a microstock site to submit your work, as of July 2008 they have rejected every image I have uploaded as 'not what we are looking for' or 'poor composition despite' the fact that those images are selling on both micro and midstock sites, of the portfolio (28 images) they did accept back in 2006, I have made 0 sales over 2-3 years.
I'd be interested to hear from anyone with imagevortex earnings, and from anyone who buys images from them regularly.