I like the 88 over the 500 for the safety. In the pistol grip config for home defense, you can't reach the safety on top of the receiver of the 500, without letting go of the grip. The 88 has a trigger guard safety
I like the 500 over the 88 for the forend. The 88 has a pinned forend which negates the use of after market 500 forends without spending a bunch of money to convert it over.