Why did I arrive to this conclusion so sudden ? After all, I have the iPod for over a month and half now and never really used it for anything beyond podcasts/music/videocasts.
The answer is simple: 1.1.2. The Firmware update that appeared during last sync upgraded the iPod to latest version which (in addition to obligatory bug fixes) brought the long needed possibility of adding an event or modifying an event in calendar or adding/modifying an address card.
With this in place, I can finally use iPod as the PDA - because you will get information about some new address or phone number change most likely when you are not at the computer or online and without this feature, there would no way how to capture it. I tried to use pen and paper - but it is so easy to loose the paper or forget to enter it ...
Because all of my calendar data are living in Google cloud, I needed a way how to sync iCal data from my Mac with Google. There are at least 4 different ways how to do that:
1) SpanningSync - the subscribtion based product
2) gSync - very affordable program from Macness.com
3) OpenSource Java based GCalDaemon - very interesting but with fairly lengthy setup
4) using free Plaxo pluging for address book
I was looking into SpanningSync before and even evaluated it, but I think the value of the service is not worth of $25 a year. I would not mind to buy the application for that price, but for paying every year it is too much. Besides, SpanningSync runs your data using third party server, which is another issue - you pay twice: on top of dollars, by giving up control over your data.
The gCal offers much better price/performance ratio - for one time fee of 10 pounds you can use it as long as you wish - or as long as Google does not modify their API. I cannot comment on it's functionality, because I ended up using the #4 solution.
I have been using Plaxo already for over a year to keep address books between different platforms in sync. It was then the only practical solution how to synchronize Thunderbird contacts, Address book on Mac, Outlook contacts and Yahoo. Now it can in addition to synchronizing address books also synchronize the calendars and added the Google as data source. The contacts synchronization is one-way only (you can load your contacts from GMail to Plaxo), but calendars are synchronized both ways without any issues. Plaxo basic service is still free, if you want premium you can get de-duplication option and synchronization with LinkedIn. Unfortunately - same as with SpanningSync - the value of the service for me is not as high as their price. YMMV.
I have downloaded the addresses from Plaxo, synced them iPod and tested that you really can edit or add an appointment in your iPod and that with the next sync it makes it up to the cloud and shows in your Google Calendar. And vice versa. If you are online, the updates in address book or iCal are synced almost immediately to Plaxo and with short delay to Google.
Few recommendations: after adding Google sync point and setting up the link, do one synchronization and then switch the contact synchronization off (keeping the calendar sync only). Why ? Because your Google contacts contain most likely just a names and emails or even emails only as Google extracts them from the emails arrived. After sync, you will want to clean up and consolidate your data by assigning the newly collected emails to people in your address book and deleting the incomplete records. Without switching the contacts synchronization off, you will have them back and can start the deleting again :-) - as I learned the hard way.
It is also important to understand to which calendar are the newly created appointments from iPod added - especially when your settings in GCal and iCal do not 100% match.
Now back to the subject: why is this the best PDA ? I was using several Palm based devices as well as Windows Mobile based PDA's (one of them - the Toshiba e830 is still being used as eBook reader) and every one could synchronize the appointments and addresses. The largest difference is the Touch user interface - you have to try it to understand. None stylus based Palm or PocketPC came ever close to the simplicity and functionality of the Touch. Not speaking about the beauty of the UI, of course.
Second reason for being the best is the tool chain behind the iPod. Syncing using iTunes and Mac / iCal / Address book is by order of magnitude better user experience that using ActiveSync and Outlook. True, using Plaxo you could move the data from iPaq to Google same way - or maybe the new Outlook is even Google aware - I have no idea because I stopped using Outlook in 2005.
And last but not least reason is that NONE of my previous PDA's could serve as iPod, show images or video or even surf a Web via WiFi. I stopped using WiFi on Toshiba PocketPC after it was obvious that for 99% sites the pocket version of Internet Explorer is simply unusable. I stopped trying to use it as music player because to play a song you had to use stylus and both hands. And the music stopped when you switched the device off, so instead of enjoying the podcast I was fiddling around with screen light settings to get at least few hours out the batteries.
Now if the iPod had at least small (1-2 MPix) camera, it would be almost perfect ... but for that I guess you need to get an iPhone.