I have used both types of distance calculation in different campaigns. I agree that the 'alternating' rule is better, but I've also seen that it confuses some players and in that case slows down combat.

I'm currently using the phb rule. My players have just gained access to fireball and similar AoE spells, and I use the actual circular spell effects

So far I have not seen the players actively abusing this, so for now I'm just ignoring the weird distance effects