Either choice is a good choice.
Regarding sound, For every 3 db that you drop the power of the sound is approximately halved
I think the lowest price Bosch is about a 50db max and the one you are looking at, at 40db, is virtually silent.

Both clean equally in their respective auto wash cycles

The miele line is basically the same top to bottom in terms of construction. As you move up you get more insulation like a top pad and rubber strips for the toe area. This accnts for much of the Q level gains.

Fact is, most people cannot tell the difference between a few decibels on a DW in typical residential kitchen.

They'll both clean well and dry dishes provide you use rinse aid. Your tupperware lids are still gonna have water in them regardless of your choice. But, you can place them anywhere you like, not just on the top rack.

Be careful with those warranties ! If you must have one, only buy it from the manufacturer, not a third party or the store.

I'd base my choice on how well I liked the rack configuration and how it handled my dishes and silverware.

I have owned both and they are both good. Both dry very well contrary to lot of people complying about Bosch. Lot of misinformation on these forums that will make you believe that Miele are far superior. Given your choices I would buy the high end Bosch hands down for its low decibel. 55 db is unbearable to my ears (my last Miele)
Vinyal

Decibels, schmecibels. Depending on how my "42 dBA" Bosch is loaded, I either hear it or I don't. Just like my old Miele, no better no worse. They're both very quiet relative to some of the noisemakers out there, and on their worst day neither would be overly offensive to someone dining a few feet away.

I don't think the issue is sound. Either will be quiet enough for most.

Do think it's wise to look at the cycles because that model Miele is very basic. There is the cutlery tray -- does the Bosch have that? If not, then go with Miele.

The important thing with the dw IMO is flexibility and being able to use it as you need. Does the Bosch offer anything you need that the Miele doesn't? How do they compare in terms of loading?

I've had 2 Mieles and personally wouldn't buy another brand but this case the Bosch may be a great choice if it offers more for the same amount.

Second what xedos said about the waranty. I bought a Miele washer/dryer and their extended was less than the dealer's.

With my Miele Dimension Plus that I've had for 4 years, we purchased the warranty directly for Miele for $250 for 5 years. This is the only way to know for sure that Miele tech comes out. We've had them out here twice. The first time was a year after we had the unit, the overflow protection sensor was tripped in the lower pan. It turned out that one of the newer detergents was making too much suds. Then a couple months ago I noticed that the coating on some of the racks were chiped away and there was some rust. So I called Miele and told them, they sent up an appointment and the following week a tech came out and installed the racks. I could have done that myself if they would of just mailed it to me from the warehouse in NJ, but they said it had it be done by the tech under warranty. Next April the warranty ends. I just hope the unit stays working OK after that, since it was about $2200 when we purchased it.

About the sound. Mine is a Q2. I did see a working La Perla that was a Q5 and it was slightly quieter. But the more dishes, pots, pans, etc that is in the unit, the less you will hear the water spraying around.

Many of the recent Bosch DWs made since this summer are about 2" deeper front to back than either older Bosch models or current Mieles for added capacity. That may account for the sale price on the old Bosch.

Thank you all for your help! We took our dishes over and actually liked the Bosch racks better, partly because the racks in the Miele are the lowest end ones and buying better ones on eBay would add another $150-$200 to the already $250-more-expensive Miele. Basically my thinking was, I'd love a Miele but not this one--someday maybe I'll get a higher-end Miele but for now the Bosch is the right choice for us. It has all the bells and whistles (half-load option, 3rd-rack cutlery tray etc.) for only $899.

Thanks again!

ideagirl2, I'm in the same position you were in and am considering either the high end Bosch or the lower end Miele. I'm inclined to go with the Bosch as you did, but was wondering what your experience has been since you've been using it. How does the Bosch dry? Since it has a condensation type drying capability, do things tend to stay wet? Thanks for your help!

I'm not ideagirl2 and I don't have a Bosch, but I can say condensation drying works very well. I have a stainless tub GE that can do heated dry but I leave it off so it does a condensation dry (although it may not dry as well as Bosch because I don't think it heats final rinse water as hot as Bosch). I don't even use rinse aid and mostly everything except plastics are totally dry. Then again I have very soft water. If you have harder water you will almost certainly need to use rinse aid.

I do have a Bosch (800 series) and it dries very well. In fact, yesterday my DH was unloading the dishes right after the DW was run (usually its hours later) and commented that he thought the DW didn't have heated dry - well, it doesn't, but everything was both hot and dry, from the heated rinse I suppose. I do use rinse aid.

Great! Thanks for the quick replies! My decision is made. :)