Thanks for the link. Your concern about Cassini having to stop collections while transmitting data back to Earth might not be as serious as it first sounds. From the link you provided (in the paragraph about the solid state recorder:

Cassini spends about 15 hours each day actively observing and conducting science measurements, and it has only nine hours to return the information to Earth during downlink sessions. The spacecraft sends an average of 500 raw images during its daily conversation with team members here on Earth, but the short "call home" may not offer enough time to transmit all the information collected. Often times, the spacecraft will not complete the data transmission for a couple of days.

The limitation on the number of images transmitted each day appears to be based on the amount of daily range time on the Deep Space Network (DSN). There are a limited number of DSN antennas to support multiple missions. There doesn't appear to be enough range time to transmit all of the images Cassini will collect in 15 hours each day, so the ability to collect and transmit simultaneously doesn't appear to be a serious limitation. All it'll do is delay the data transmission by a few hours. We've waited for years to Cassini to arrive at Saturn. We can wait a few hours to see the images.

Potentially, there could be a problem if Cassini ever develops pointing problems. All of those attitude changes to collect images then orient to Earth for data transmission could prove difficult in the long term.