The earlier lens - 55mm thread, bigger mount, metal build quality - is also known as the Leica Elmarit-R 24mm f/2.8. Minolta made that lens, and the two are twins. The later lens is also known as cut-down plastic attempt to copy Canon, Pentax and others and make smaller lenses at low cost.
There is really no contest, the original wins. It is slightly more prone to into-the-sun flare. If you can find a rare VFC (Variable Field Curvature) MC version, or an original pre-MD MC version of the plain 24mm, these are from the Leica co-operation period.