The iPad syncs at least once a day, and often more.
Apart from iTunes being the largest space hogger software ever written for Windows, does it do it's job.
Initially iTunes syncing may not make too much sense, but after a while it just works. iTunes has not once deleted data and even it if would, I could just restore the backup from the day before. I rather sync too often than too little and it's not like syncing requires much input, just plug-in the USB cable into the computer, the rest is done automatically