I also have the Octavia 1.6 CR TDI, with a DPF, purchased in October 2011 and has covered 23500 miles, not once have I seen the warning light, we do a lot of driving around town, and after some research on the whole DPF regeneration, it turns out not a lot is required to regenerate it.

running the engine above 37mph for 15min's and RPM above 1500

This is pretty easy to achieve in most cases, and if not, when the light does come on just take the car for a long run on the motorway for half hour or so...

It is all down to the way people drive. If you drop down one gear, the engine will rev up more thus the engine temperature will go up together with the temperature of the exhaust gasses.

I've now done 36000 miles in my Fabia in 3 years and havent had any problems with the DPF. I do about 20 journeys a month of about 3 miles but the rest of my driving is generally 15 miles or more. Plus we frequently have days out to give the car a run.

 

It's down to lifestyle and choice. I`d cycle those 3 mile journeys if I didnt have to ride up a damn great hill at 0530am in the morning to catch a train!