Man, I've expended a considerable amount of mental energy these past couple days contemplating selling my pedalboard and using a Studio 40 as one to feed the 500H instead.
My biggest factor in deciding nah was that it'd still be a thing to hook up with just as many cables as the pedalboard and the Rumble 500 sounds the way I want. So really I wouldn't be buying for amp sims, and being as picky as I am about dirt pedals I figure I'm better off with my current setup.
That said I am replacing the SA Aftershock with a $30 fuzz pedal and an MXR bass distortion. I've really tried to live with the Aftershock but it's just too bassy and when I try to dial it out I just make things sound worse. I am just not good with distortion. Last time I bought a cheap fuzz I found the cheapest one available with a blend and I've never found one I liked better. So here's hoping lightning strikes twice! And if it doesn't I'll try and make a fuzz out of my 3 pedals.