I really don't enjoy milk or cream in my drinks at all. As far as the quantity is concerned, I normally use the double carrier (15g or 20ml by volume), if I make that as a stand alone in the day, I mostly use about 30-60ml (c2-3x by volume) in the morning I do make it longer (and, repeat twice for a mug size) and it still produces a different flavour to filter made. Post prandial I will tend to make it around 1:1 by volume.
While I'd lay claim to that product of my current basic machine being acceptable (certainly to me), it fails abysmally at ristretto. As a product, it is positioned at the "high end domestic-sub coffee specialist" level, with the current version espresso standalone costing about £170, giving decent pump and temperature control, with fast ready being implicit (otherwise it couldn't maintain temperature during flow). I suspect its replacement will be a better grinder (straight to portafilter) and stand alone maker, rather than b2c