The HTC Titan is big for a smartphone, heavy and solid with a 4.7-inch screen, just under 10 millimeters thick. The back is rounded plastic, which feels fine to hold, though there's no rubbery texture to help your grip. There's a small button on the bottom edge that looks like it will allow you remove a piece of the back, but when you press it in, the entire back half of the phone comes off, giving you access to the battery and SIM slot.
Even though the phone's screen is the same size as the Samsung Galaxy Nexus, it doesn't feel like as much of a behemoth. This may be because the Titan's thickness rounds out the other dimensions a little, and the phone has less real estate devoted to top and bottom bezels than the Galaxy Nexus. Yes: the phone feels smaller because it is bigger. It turns out the Galaxy Nexus doesn't feel big, so much as it feels disproportionate.