We know, you're packing furiously for your next shoot tomorrow, but look -- you need to sit back for 12 seconds, give this article a once-over, chime in below and take one of the biggest sighs of your life. As unprepared as you feel, everything's going to be alright. We promise. Now that we've got you in a proper state of mind, we're curious to know how you'd change Canon EOS-1D Mark IV. The outfit's latest and greatest professional DSLR has come out shining in nearly every review we've seen, and while it's rather massive in stature, it's loaded with features. For nearly five grand, we suspect that you'll be pretty critical on it, and that's exactly how it should be. Is the low-light performance satisfactory? How's the speed and handling? Has it revolutionized your business? Are you a Canon fanboy (or girl) for life now? Spill all down below, cool?