Quite simply, the default editor is pretty horrible. It is tedious to use as its features are fairly exiguous. Maybe I'm too used to Dreamweaver, but this creator is pretty awful. For example, it won't let me create a link in an empty field without having text in there first. This is a pain as my left-hand menu only contains links. It also will not let me use any form of Kana/Kanji in place of the homepage (i.e. ホーム). I have to create a link with a name, delete all but one character in that link, type in the Kana/Kanji, and then finally delete the last letter for it to work. Quite a pain....
Keep in mind, I'm using those "special experimental features" that Google talks about. I didn't notice much of a difference between the two options, honestly. I'll stick with it for a bit, but I don't recommend this to anyone. The only good thing is the fact that they give you 100 megs of space for free.
One thing that keeps bothering me is the obvious lack of anonymity when it comes to spam filters. It is obvious what my email is by the URL of this page. Anybody can create a simple bot that searches every "*.googlepages.com" URL and automatically adds them to a mailing list. Some people have done experiments to find there has not been an increase in spam, but I'm still skeptical. Hopefully Google will address this by allowing users to change their domain name by at least using some form of DNS masking. Simply bumping up spam filters is only a temporary solution to an obvious problem....