I just got my Steel/wasabi Side Effect yesterday also. What a useful little item! Got an aubergine SE for comparison -- adore the color, but prefer the "flex" of the Dyneema fabric.
En route, the Dyneema SE is perfect for my "seat pocket" stuff (bulky cheapo headphones, iPhone, TB wallet, gum, puzzles, pencil, fold-up reading glasses). I always wrestle with the dang headphones because they hog space in a carryon (and haven't found other headphones that work better), but they are tamed with the Dyneema SE. The headphones do not fit well in the aubergine SE. I'll use the wider strap from my Breve for day use.