The HTC Titan is exactly the sort of Windows Phone Microsoft wants to see from its hardware partners. It’s a big and beautiful slab of technology that invites great debate while still conforming to the chassis specs coming out of Redmond. The main question stirred up by the arrival of the 4.7-inch Titan is, inevitably, how big is too big? Ever since HTC’s own HD2 established 4.3 inches as a viable form factor for smartphones, that’s been considered a sort of ceiling for comfortable use, but this year Samsung has strayed beyond it with the 4.5-inch Infuse and Sprint Galaxy S II, and LG’s looking to do the same with the 4.5-inch Optimus LTE.

The age of the extra-large smartphone may be upon us, whether we’re ready for it or not, but that’s not the only new wave that the Titan is cresting. Along with the 3.7-inch Radar, the Titan is HTC’s contribution to the new generation of Windows Phone 7.5 devices, which are gradually making themselves known to us as we build up to the holiday buying season. Thus, a less obvious yet equally pertinent query we must answer is whether the moderately improved internal hardware is worth the upgrade over a Mango-updated first-gen WP7 handset.