What I can say in a neutral way is that perhaps the most important difference between gSync and Spanning Sync is - gSync speaks directly to Google whilst Spanning Sync uses a service in between. gSync supports more google accounts.

gSync is more similar to iSync - just thing about mobile devices as about your Google calendars…

… and both products has to deal somehow with beta status of the Google service :)

(I assume you are the developer of gSync; yes?)

However the catch is the PDA.

I use a PDA smartphone. As a Windows Mobile 5.0 device it syncs with my M$ Calendar and my M$ Outlook. Tough to drop that feature simply because I want to leave Micro$oft….

Google needs to have BOTH a browser only client interface, AND a PDA sync capability.

I still want and would use Gmail IMAP if it were implemented. Being able to create virtual mailboxes of Gmail mailstores with non-web client apps would be cool. I haven’t found my ideal virtual mailbox solution that eliminates the need for shuffling messages between different hierarchically-organized “physical” mailboxes.

if IMAP support for MailTags is reliable/robust I might seriously consider reducing the number of IMAP mailboxes I current have. For me, a well-implemented message tagging/labeling system could supersede message filing, presuming the former can be essentially a functional superset of the latter. I don’t need no steenkin’ mailboxes. Well, just one. :)

It is always helpful to remember that Google is an advertising company - their revenue is dependant upon people accessing their content, so as you astutely point out, their services will be more closed and inwardly focused that others.

That is, you cannot publish to Google calendar from iCal (or Sunbird or any of the many other ICS calendar applications). It’s true that you can publish your calendar to a place like iCalX (http://www.icalx.com/) and then have Google subscribe to that calendar so you can VIEW your iCal calendar at Google, but you cannot publish directly to Google. If you could, you could use Google instead of iCalX for your calendar store. What’s more, you could sync iCal and Google Calendar so you could do calendar management from either one and have the other automatically sync the next time you open it.

Some people on the newsgroups have faith that Google will someday implement calendar publishing. I don’t share this faith. It allows people to use Google without having to actually log in to Google. They get ad revenue and usage statistics when people login to Google.

Google wants to get rid of all applications (like iCal) and force you to just use the web version. People point out that you cannot do calendar management on a PDA until you can publish to Google. However, I think Google is banking on people getting Internet access on their cell phones and PDAs and running a “Google Calendar mobile” on the phone that is similar to their “Google Local mobile”.

A while ago, people wanted Google Mail to support IMAP. (perhaps with virtual folders based on tags) This too allows people to use cool Google features without having to actually login to Google’s web interface. It’s the web interface that’s key, and Google won’t do anything to discourage people from using the web interface.

So keep in mind that if you endorse Google calendar, you’re going to be endorsing the end of local computer applications. It may be true that being all-Google is better than being all-Microsoft, but don’t pretend like being all-Google is going to be good for any SOFTWARE DEVELOPER other than Google.