Well, I guess it just comes down to two main issues. How much time and money do you want to spend building a tour, and what is the most appropriate style for a tour?
As for time and money, I believe Mapwing wins out. I've built hundred point tours in a week. This includes shooting them too. How many other tour formats are taking on projects that big? Then, what about the end product? Java applet, proprietary plugin, quicktime, the average user hates downloading more stuff. We on Macs are spoiled as we have wonderfully integrated quicktime. Ever try that on XP? Try a 30meg download. That is totally unfair for the end user, in my opinion, just to look at a tour.
Also, my experience has been that while photographers and purists like panoramas, many consumers find them frustrating and disorienting. The biggest complaint I have gotten about panos is the spinning navigation coupled with the distorted image. People complain it makes them dizzy. Now, panos can be done right, but at what cost to the creator and the end user? I'm not saying Mapwing is the be all, end all of VR and VTs. I just don't understand why everyone gets so hung up on panos, when many people really don't like them.
As for price, well, I guess it comes down to what your time is worth. The sooner I can complete a tour, the sooner the client sees results, and the sooner I get paid. For what it is worth, there is a company in Mendocino using Mapwing to cataloge the entire town, then sell advertising and integration to each business.
http://walkmendocino.com/ I'm not sure if they were able to take on something like this before Mapwing.