Ahh sorry. For what it is worth, I will give my own opinion.
I have looked at domainzaar myself many times and always been tempted put always been put off by how easy it all sounds. The perpetual 50% off for today only creating the "urgency" of the purchase doesn't help either because it still leaves the price just outside my "oh well it was a worth a try" range.
gecoparking looks better than when I last looked at it. They seem to have spent time it on recently but its price is also not throwaway plus unfortunately there seems to be xml errors on their demo sites. I am sure easily fixed but doesn't really inspire.
Bottom line. The parking pages of both look better than most other parking pages you see but neither has convinced me to spend money.
edit: I see gecoparking does have a 'live test'. I may give that a try when they fix the xml issue