When I bought my 1DsMkII, I asked the seller what he used to keep the sensor clean and he suggested I get what he uses and based on his recommendation and what I have read here on this site, it seemed like a sound choice.
So far, I've only had to use the kit once to do a thorough job and since then I've changed lenses numerous times and haven't experienced any problems and of course, would use my bulb blower first if needed and the kit as a fall back alternative.
I'll let you guys know how often I have to use the kit. Prior to having it though, I had my 5D for a little over a year and ended up taking it in to a local shop for a cleaning and they charged me 60 bucks and had to leave it with them over night so I figured now with two FF bodies, the kit will pay for itself eventually.
Cheers!
In the end im using Sensor Swab type 3. it did the best job on my 5d after trying almost everything.... even one of those little vacuum cleaners that you put on the sensor almost, what a rip off that was 
