I'm sorry but low RAM usage is not good performance, those are not the same.
Also, I've read somewhere that all memory not in use is wasted memory. I find that thought really interesting. If an operating system would be able to always maximize RAM usage by loading every peace of software and information it uses or is about to use without using swap or a pagefile it shoud be more responsive I think.
I haven't found any third party stores with steam decks in stock. There are some who sold the old model so maybe in some time there will also be OLED versions available.
It's not officially sold in Switzerland. I could order it to a german adress but I would also need a german payment method which I dont have.
Sadly, I still can't buy it in Switzerland.