So, I found a good deal on a normal 840, not a pro 840, and I want to know if its enough to want to get it. I've heard the 830 is more reliable and fast, but I want to know if its enough difference to pass up on it. It's basically, save $30 and get the 840 or spend the extra $30 for the 830. Anyone know if the 840 is a good idea?