How can I sync the standard KDE PIM calendar and TODOs attached to it with an Android device? I do not want to play with Google calendars / services, just use Android native calendar app with my desktop calendar being sync across devices.

As far as I know, Android does not support many types of calendars. Some time ago I tried to use OwnCloud and CalDav-sync in Android and it worked to some extent but it has not supported TODOs yet.

What options do I have? Anyone using such a functionality with success? Please, share your thoughts!

I use an Asus TF201, but I do in fact use Google Calendars synced with a 3rd party app (Business Calendar from Appgenix) on my tablet and using either Chrome or Korganizer on the desktop. At this writing everything syncs very nicely. Full disclosure; I'm not a "power user", but I use it daily for appointments and notes. To-Do's is on my list to engage as soon as I figure out how I want to use it.

Having said that, either Akonadi or Kontact (Kmail) in general drops my connection to Google on occasion. Don't know why yet, but logging off and back on resolves the issue for the next few days (I rarely turn the PC off) .