I handled the T3i a couple weekends ago. It feels like a toy. I handled the D5100 at the same store (Best Buy), and it felt slightly less toy-like. I dunno...I would rather have the Nikon, but this price point and these two offerings is NOT a slam-dunk matchup in favor of Nikon. My gut tells me the Nikon has a better, color-aware light metering system, and that the T3i is dumb and color-blind like 90 percent of Canon's camera models are. As a point and shoot type d-slr, my feeling is that Nikon's color-aware, 3-D RGB color matrix light metering, and 3D, RGB-measuring, color-aware flash metering with a GOOD lower tier flash like the SB 600 or SB 700 gives the edge to Nikon for the beginner. I am not impressed with Canon's lower-priced flash. With color-blind metering, Canon always had trouble with consistent, easy flash-metering, for years, until the 580 was upgraded to the EX-II generation. Nikon has a 15 year head-start on color-aware metering. I am assuming that you want a the camera to be able to be used as a P&S camera for all types of images, both with daylight AND flash, so my nod goes to the Nikon system on both ambient light metering in auto mode shooting, and flash metering. AND, on better, lower-tier flash units.