I tend to agree with William. While you can probably crank a keyed chuck tighter, in my experience my Jacobs keyless gets tight enough for all my drilling tasks. And they do tend to self tighten.
My typical drilling operation involves multiple bit changes so I certainly wouldn't want to give up the keyless convenience. And my press is direct drive, so no belts to slip. If I am over driving the drill it's either going slip at the bit or the Morse taper in the quill, and I would rather the former.
A tip, should your keyless chuck become too tight, a couple of inexpensive (rubber) strap wrenches may provide enough "persuasion" to release the bit.
Another tip, a half inch chuck will only just hold a bit with a half inch shank. If you are buying a chuck, a 5/8" chuck will have a much better grip on a half inch shank.