said by joejoejeo:R29 was a special release for Time Warner Cable and the features are new to Comcast customers.
the only real benefits I see with R29 is it seems that to have improved Startover/Lookback handling as TWC seems to have need it for some reason and A28 did not work out too well for the startover/lookback features. Also R29 is basically the introduction of Lookback, Startover, Caller ID on TV, and Possibly remote DVR for TWC customers and adds features in the last two iGuide A28 updates.