Hi Cata,
Yes, ground flavored coffee can be used this way and stored there. It will probably hold about a half bag (1/2 pound). I think the flavored syrup is a better option for that machine personally. Also, it's your machine and you should enjoy it how you want to enjoy it. If you want to grind flavored beans in the system and you don't mind paying for a new grinder down the road (approx $350) then go for it. Miele invented the built in coffee system and are on their 4th generation. There's not many service issues with the machine if maintained properly. Maintenance includes descaling and cleaning the brew unit and milk system. These are all computer programs that guide you through the steps. It's a great machine!

Can the machine make a large 12 ounce mug of American coffee or is it limited to only small espresso and cappuccino?

I think it max's out at 12 oz. actually. Beyond that the coffee becomes too diluted. The machine is completely programmable. Fill levels, coffee strength, temp, auto on & off, user profiles, etc.

Yes, for regular coffee, it can make a large mug. When you press the "coffee" option, it will ask if you want two cups, which if you push yes, will give you a large mug full of wonderful coffee. If you don't push yes, it will give you what to me is a half cup, but is probably a European full cup.

I second what was said about proper maintenance. Granted, we've only had our Miele for about 8 months, but we've had no problems and follow all the maintenance as the machine guides you to do. My brother has had the Miele coffee system since 2005 and has had minimal issues.

Here's a thread from earlier in the month on Mieles. There might be some useful info for you.

Here is a link that might be useful: Another Miele thread

I forgot that my husband uses heavy cream in his coffee. Can the Miele milk frother handle this or would I have to add the cream after the coffee is brewed? I have read all the Miele threads and all have been helpful and informative.

The frother doesn't like a heavy cream. It'll work but won't produce nearly as much froth as milk. The thickness of the cream vs. narrow tubes siphoning up into the frother...

The manual says plain milk only. Another consideration: "Heavy cream" often has industrial thickeners that may not play well with the milk pump and boiler. Personally, I wouldn't try it with mine, but it may be worthwhile to give it a go if it's important to you. If you do, I would try to find cream with no carrageenan or xanthum gum added.

But seriously, the coffee drinks with foamed milk are great as is. If you still want cream then there is no harm to add it afterward.

With heavy cream you might end up with cheese on the inside. Not cool.

This is actually heavy cream straight from the cow, not even pasteurized but I can see how it would clog up the lines as it is very thick. Does the coffee come out of the machine hot enough that it would take cold heavy cream and still be at a decent temperature to drink?

Yes, for regular coffee, it can make a large mug. When you press the "coffee" option, it will ask if you want two cups, which if you push yes, will give you a large mug full of wonderful coffee. If you don't push yes, it will give you what to me is a half cup, but is probably a European full cup.

Spio, it will do that but you can also program the amount to make a larger cup of coffee all the time if most of your cups are larger like ours are. Hit settings, then prog the amount, then coffee, and it will keep brewing until you hit the stop button. That amt then becomes your standard. When brewing any cop you can always hit stop sooner if you just have a tiny cup, or just want 1/2 cup.

That also works for the other settings as well, e.g. settings, prog the amt, hot water.