It's good to see some activity on this tread!!
I use mine a LOT. I was worried too about the size and weight (I'm petite 1,62 m) and it's true it's not as light and easy to wear on shoulder as my Neverfull but it is way dressier and versatile.
I usually don't carry a lot on it, but it's a good size for putting a scarf, gloves, beauty bag and other things that don't weight a lot but need a big bag. When I've traveled with it and got really stuffed it is for sure a heavy bag (lot heavier than others), but it's a nice option for carry on and you can also wear it during the day and also it can be a good choice for a night out.
About the handles, they are comfy enough to put on shoulders during summer, but I woudn't do it over a heavy coat. The good thing about Balenciaga handles is that even when the bag is stuffed and heavy, they don't "sink" into your body, they are pretty ergonomic. I usually wear it by hand.
Go for it! It's a great bag, you won't regret