Alternative take on negative HP

Artwork by Larry Elmore - larryelmore.com

This came to me in one of those random thoughts that I have when waking up.

The 1st Edition AD&D Dungeon Master's Guide says: (p. 82):

When any PC is brought to 0 hit points (optionally as low as -3 hit points if from the same blow which brought the total to 0), it is unconscious. In each of the next succeeding rounds 1 additional (negative) point will be lost until -10 is reached and the creature dies.

It hit me that it's probably unlikely that Hercules the Hefty Fighter and Wizzbang, the Not-Hefty Wizard are unlikely to sustain themselves after 0 hp at the same rate.

In my campaign, PCs start out with max hp from their hit die. That includes any bonuses coming from their Constitution attribute. So why not use this as their flip side for negative?

Examples:

• Mages can survive to -4 (+ Con bonus). The max they could go, assuming a Con of 18, is -6.
  
• Fighter based classes could survive to -10 (+ Con bonus). That means a Fighter-based class could survive to -14, if they have a Con of 18! Take that, crazy not-dying wolverine!

I kinda like it, although I'm pretty sure players themselves might not like it. I don't think I'd use this on my current set of players, since we started out with the -10 assumption. Maybe if I started a new campaign? I dunno.

So for those of you who play realistic D&D, maybe this is something you'd like to add?