I purchased this purse to replace a smaller overland tote (I think it is the Donner bag).  I still love the smaller purse but I found I still needed to carry a diaper bag.  I love that the Sierra is big enough to carry a few toddler essentials plus my daily stuff.  It works great as a carry-on bag for work trips.  Would be a tight squeeze if you wanted to carry a full sized lap top but for tablet, phone, wallet, and some other essentials it is wonderful.  I enjoy that I can fit up to four water bottles/sippy cups as needed.  I also like that the bottles are all on the outside of the purse so the main compartment is saved from small leaks.