Sorry to be the bearer of bad news, but the K5 is an inferior comparison to a K6 silent. I have a K5 and a dozen or more K6's (some silent and others auto). The K5 looks almost identical in size/dimensions (very difficult to pick the difference), but it has these very small burrs, almost similar (I have'nt checked for sure) to a K3. My K5 is very slow and quite noisy, even though it's had light usage (for that very reason, it stays in a box in the warehouse). If someone has sold you a K6 silent and you received a K5, in my mind that's a pretty big difference. It could be that the seller was not well informed, or had been told the info by another person. I would say it's akin to thinking you were getting a BMW M5 and then receiving an entry-level BMW 3-series. Still good cars, but....... Sorry, I hope I have'nt been too harsh in my comments - the K5 will be OK if you don't need speed as the motor is big (will last a while) and the doser system still has that great Compak action which is cleaner than a lot of other brands.
