Upload & Sell: Off
I bought the MoneyMaker early last week, and messaged Matt (Swaggart) to see if I would be able to get it by the weekend to use at a wedding... well, he pulled some strings (being out of town) and it arrived on Friday (just in time!)
I didn't bother to adjust the straps as it felt comfortable when I put it on, but I shot with the MM plus 5D2 with 35/50 attached and 5D2 with 85/70-200 attached all day (12p-11p) with no issues at all. I would occasionally unattach a body when I knew I wouldn't switch between the two bodies & the weight of one camera on one side wasn't very noticable or uncomfortable. I woke up the next day and wasn't sore around the shoulders either, so overall I think the design works well.
Now, this system is a different system then the Spider/belt system, so I don't think it's worth comparing the two... I think the Spider system works very well for those that want to take the weight off your shoulders (I also own the single camera system) but the MM is works well for those that want to combine comfort & style. So, both work well, it's just a matter of preference & taste