For spring - definetly. I think grey is a fantastic color for the transitional months, particularly because it looks so good with white or cream. By transitional months, I mean those when it's still cool enough outside you might feel funny wearing bright colors, but not cold enough to want to wear darker, wintery colors. Does that make sense? Lately that has been my craving. Spring is in the air, so it doesn't seem right to wear black and deeper jewel tones. Yet, it's still not warm enough for turquoise and pinks and other brights.
For summer? I would still wear grey but with pops of bright colors like turquoise and pink. But I would look for a grey bag that is more of a blueish grey or is lighter - these look a bit charcoal to me. Something like this (for color only):
http://www.zappos.com/n/p/dp/48585586/c/4854.html
http://www.zappos.com/n/p/dp/48595082/c/401.html
The third one you link to is more around the light-grey shade. The other two are a tad more fall/winter to me.
If you tend to wear bright colors on your clothes and shoes, then a more neutral bag like this would be wise to own.
My favorite bag for spring/summer is my cream one, but it's not practical if I'm wearing a cream coat. If I didn't own so many grey tops, a grey bag would be a good option.
