It's really easy to keep clean. I carry mine in the rain because there isn't any vachetta on it to worry about getting wet. It's really simple. Just take care of it as you would any other bag..don't bash it around or deliberately get it dirty, of course, and you should be fine. It's pretty easy to take care of. Here's a pic of my Jasmin:
I have a manadrin speedy 25 back home (meaning no pic with me right now) and I've had it for over 2 years, never cleaned it yet, and it looks fine. I wouldn't be too worried about it getting dirty unless you let it roll around.
Go for it!! The mandarin is such a pretty color. Initially I had concerns about the bright color and after selling some mandarin items and having huge regrets, I realized how much I missed it and had to repurchase them so I wouldn't hesitate about it. It adds a nice touch of color!
I love mandarin epi! I had a mandarin ludlow a while back that I purchased at the same time as my khaki noelie (I adore bright accessories in the depths of an otherwise darker bag!) It's a shame that little ludlow was too small for my needs, so I sold it. Since then, I've been craving something new in mandarin epi. A speedy 25 would definitely be at the top of my list!
Epi is wonderful and nearly indestructible, too! You can clean the alcantara lining with Woolite if you get pen on it, and on the outside a Mr. Clean magic eraser can take off light marks (but rub gently, or the color will come off, too!)
The only probably with Mandarin Epi is I have heard a few people got bags where the dye was kind of strong smelling. So if you can handle (and smell) it first before buying that would be best!