I've had 9250 dryer for two years. It does make more noise than the washer but there shouldn't be any "rattling" noises in there. Unless you can isolate and diagnose, I'd vote for service call. The "hammer type" noise is probably water-hammer caused by the fill solenoid when it snaps shut. Annoying but not uncommon. Usual fixes are 1) check supply pressure to be certain its within nominal spec and/or 2) installing an air bladder in the line to absorb the shock. Both are pretty easy and not very expensive. Sometimes the addition of a rubberized supply hose to the machine will provide enough cushion to eliminate it.

For anyone reading about this question--installation is key. I've had 2 Miele washers installed in my 1906 house on the 2nd floor, without any special setup. First had noticeable vibrations at the super high spin speeds that the washer can do. It was workable and we had it that way for about 12 years,doing a ton of laundry, but it did vibrate some @ high speeds. Second machine W3038 has VERY amazingly little vibration/noise even at its highest spins. Not really a difference in the machines, its that the second one was installed by Miele while the first one wasn't--I thought we'd adjusted the levelling well, but obviously not as well as the professional Miele installer. I was very pleasantly installed to find out how little it now vibrates or makes noise.

The "Periscope" pipe or solution mentioned above is a quick fix, but they are surprisingly very very inefficient. At 7 minutes into the vid the fitting is tested (.50 wci of pressure delta). http://www.youtube.com/watch?v=cFOHGVhmyQA name of vid: How to reduce your clothes drying time and save energy costs The Dryerbox option is more work, but if the retro fit box installation goes smoothly, the benefits are huge. Here are links to installation pictures and instructions: bottom of this page: http://www.dryerbox.com/photo_gallery.htm instructions: http://www.dryerbox.com/pages/retro/index-500.html Generally it takes about 30 minutes to complete.

Megan Morrill-Denton, several people here offering a lot of good points. Since you've cleaned your ducting, I can't think of any other ways to improve drying, and you've mentioned you really don't have any length to the outside except 10" - though if you've got the 'corrugated' type ducting, straight galvanized might help a little. You've also mentioned that the ducting to the dryer isn't kinked... so I've no further help on that other than to suggest you use electric foil tape when you connect it to the dryer - we only had the clamp initially and it did a poor job of holding the duct leak-free to the dryer. You mentioned a cold floor... we had that issue - the whole room actually. When we pulled out our old dryer, I noted cold air flooding from the corrugated duct coming out from the wall (actually placed a baggie over it, taped it close to keep cold air from flooding into the room - the baggie stayed puffed with air until we replaced the outdoor vent cap). I can't really speak for the Heartland style outdoor vent other than to say once we installed that, I noticed the baggie no longer inflated with air from the outside. That was a plus for us. We previously had the slat-style outdoor vent. As dadoes mentioned, it needs painted if you don't want it to stick out like a sore thumb (it's rather big), and I used a can of plastic approved Krylon Fusion paint from Lowe's for ours. Keeping any part of your ducting and vent cap clear of lint is important, and reduces fire hazards - sounds like you are doing this. Good luck on your situation.