My father just bought a HTC One. Phone is beatifuly designed, has gorgeus Full HD screen and a wonderful sound (Beats Audio). Thanks to the powerful hardware Android just flys, works with no problems at all giving me a superb YouTube experience and Chrome for web browsing (Flash!). I really like my Lumia 920, but the lack of apps is killing me. May just buy HTC One for myself...
Design is sexy - check
Hardware is top notch - check
HD screen - check
OS smoothness - wait for 3 weeks and see it start to lag, not yet checked
If you are extremely keen to jump for HTC One, I suggest you wait for 3 good weeks, let your dad use the phone and see the phone's smoothness after 3 weeks
.
Am assuming he uses the phone regularly, installs apps and things rather than once a day to make a few calls.
There are beautiful looking devices some manufacturers make, some are
-Xperia T/S
-HTC One X
-HTC One
but they take a beating when it comes to OS, the OS acts like a hook attached to a drag car on one end and a fat pillar on another, if you know what I mean