I've had silver aluminum series 0-6 (at series 2 or 3 I tried a SS, but didn't like the added weight, and went back to aluminum).
I now have a series 7 starlight aluminum. I was really tempted to try going stainless again, but the wait was pretty long when I decided to order, and I was passing my series 6 on to my daughter, so I just stuck with aluminum.
I've stuck with 38/40/41 mm.