I know this is a little late as I read through the thread and you've already purchased, however I'll post my response for posterity.
For the last decade I've been using a Vertigo and M80 Dual, depending on the gig. I have zero complains about the M80. It's showing wear where it touches the ground when I lean against things, but that's a lot of weight resting on one spot and it's 10 years old. If it fails I'd buy a new one.
That said, I'm a recent convert to an ENKI XB-2. Functionally, if you're not using public transit, it's just straight up easier to use on stage than a backpack style bag.
I still use the Vertigo where appropriate, however for anything that requires two basses the M80 has been retired.