About driving in traffic with a manual, having to clutch etc... It's very simple once you get used to it... All driving schools ue manuals, so you simply learn with a manual and it is an a sort of "automatic"

thing to clutch, change gears, etc.
About speed changing gears, you can change gears at least as fast with a manual than with an automatic, (in the sense of beginning to change the gear and ending the change), at least all manuals I've driven against the 3 autos I've ever driven (my parent's Chevrolet Trans Sport and Mercedes CLK and the Trailblazer we rented in the US).
About the smoothness, a manual can be driven smoother than an auto. In an auto it's a machine changing gears, and it never does so smoothly and when it does, it's not at the right time. With a manual you are in control, you change when you want and as smooth as you want.
In terms of reliability, I've never had any problems with either type of transmission, but, for example, I heard loads about AT overheating in deserts, and a few burnt clutches too. But burnt clutches can be changed relatively easy, but an overheated AT may bring big problems.
But other than heating problems, as I said before, AT might be better in some other offraod conditions, and it might be quite useful for people who aren't used to MT.