Since calculating recoil energy starts with a momentum balance to determine the gun velocity - as I recall, equal power factor will equal recoil energy. Power factor is a momentum value, but with odd units. The powder gases are part of the ejecta and play a part in the momentum.
Once the gun velocity is known, putting it in the kinetic energy formula gives the recoil energy.
As stated above, many like the heavier, slower bullets for spreading the recoil energy over a longer period of time. Also, as stated, many prefer the sharper (quicker) recoil energy of a lighter, faster bullet.
Even though the actual recoil energy is the same.