Hi, I'm new to the forum and I'm considering building a commuter and all-around errand runner with the BionX D-500 kit. I'd be building the kit onto a Surly Ogre 29er with rear rack for hauling stuff and also with a trailer hitch for a small cargo trailer. I live in a hilly area in Southern California, and my commute home is almost all uphill (gradual at first, steeper as I get closer to home). I'm on roads mostly, not trails. Here's my question: does anyone have any experience with the BionX D-500 as a hill climber? Hauling cargo? I've read that hub motors can overheat on hills, especially at lower speeds, but the D series is supposed to be less prone to that. Does anyone have experience with that? My other alternative would be a mid-drive, like the Haibike Xduro Trekking, but I like the Surly frame and fit better. Advice?