I've ended up using either a protection racket or tribal planet bag. Both are seriously durable and have one decent front pocket which will take a few leads plus a lightweight amp head. The tribal planet also has decent lengthways pocket of the neck section of the bag which is ideal for a bass stand or folding music stand.
Difficult to gauge what other people think is too cumbersome. Both of these are semi rigid bags but IMO they are both light, easy to transport and comfortable to wear on your back for a while. I've also got a Benevente leather gig bag which is significantly heavier than both of these....
I'm also using a pro-racket drum hardware bag for my accessories, stands and double bass seat. Whilst this is much larger it's still a top bit of kit/design in terms of practicality, weight, toughness etc.
I am in no way affiliated to pro-racket stuff!!!