[Tubbs]

I prefer to rack the slide every time I reload. I am a lefty and I cannot always manipulate the slide release on all handguns (I know a lot of others have mentioned the same thing).
Also some european handguns do not feature slide releases thus requireing you to rack the slide regardless. I find that it is just easier to learn one technique that can be applied to all handguns.
Another reason I rack the slide is that I am not infallible and in the off chance that my gun went "click" because of a stoppage and not being out of ammo (I may not notice in a high stress situation), I will be closer to clearing that stoppage if I rack the slide as opposed to manipulating the slide release.