I use a large lightweight squishy purse or a basic
catch-all nylon bag or backpack and stuff laptop-in-sleeve, real use-on-the-street purse, and all other stuff in one of those. The purse is lightweight and holds an IBM laptop quite nicely along with a change of clothes, largish camera, book and cosmetics. It's also nice for carrying a bottle of wine or groceries into the hotel.
It's more about containing my stuff in one spot. I am a big fan of UA mesh amenity kits for holding stuff together in this purse/bag/backpack and also a drawstring bag former amentiy kit that I use for my plane-necessary items: ear buds, pen, glasses, kleenex, lip balm, comb, toothbrush, etc.
Currently the backpack is out of favor. Too many zippered pockets to look through to find something. If you're uber-organized and have good memory skills the purse/computer bag might work.
But do remember, when you go to dinner or almost anywhere you will have the purse/computer bag and will still probably need a purse.