Right, I understood it correctly, but strictly speaking, "immer" means always, as opposed to "Für immer" or "ewig", which definitely mean "forever". You are correct in saying that the slogan "Immer besser" implies that Miele is always better, no matter in what regard.
If you want to see some damned hot Markuses, you should go to the Allgäu. There are lots of them, on the other hand, most of the Wolfgangs I knew were on the fragile side, it seems.