In terms of PR I dont think they are great. So many have too many outbound links. However, I am dazzled by the SERP results. I do own a few word cloud sites, And Im always surprise that after 500 backlinks I usually end up way high in SERP result. Average third position for Permanent text links or whatever Title I put on my main page. Third position out of 186 million results. Google seems to like them, and I think it's because of the randomness of the links at every view of the page. Robots must be confused. However, I have never seen a word cloud page rank high when they have more then 100 out bound links. It seem to be coinciding with Googles webmasters guideline. I also notcie, that if you check backlinks in Google or Yahoo, I was unable to find a backlink of a word cloud that has more then 100 outbound links. Google seems to frown on those. My word cloud are built from scratch. I resgister domain for 3 years, No drop domains, purchase and exchange backlinks. All now average 1500 backlinks and are limited 99 outbound links. In the last period before the Google PR update, I bougth word cloud links, not all of them, but many, and IO have pass from PR4 to PR6 Also, People say they have zero effect and are bad, however, when price is cheap or even zero dollars, many who frown and judge word clouds, are the first to submit their site. why ? isnt suppose to be bad ? My saying is , a link is a link.
Thanks for the well thought out response Camay I recently bought a single PR6 text link from a word cloud site, pointing to a recently launched niche blog. A few days later the Google PR update happened and the site was instantly a PR3. Not a bad way to spend $15.