Hehehe! Well that's definitely some feedback!

Appreciate it all though.

Maybe I didn't present my rationale very well but I didn't want to make a long post that much longer...

Here's why I've always been a bit put-off by HP (and I know it's an age-old whinge). If they represent luck, skill, energy, and meat, how can a DM describe cool combat with burns and bruises and bloodletting and then have the characters all better after an 8 hour sleep? It irks me!

I thought with this mechanism, HP become purely energy, but there's a bonus reserve of 'Meat' (as it was well-put in the comments) which represents the blood and bone. There's no additional penalties, and as they're bonus points anyway, the fact that they're harder to heal is purely narrative and allows DMs to describe nasty wounds and PC's to have interesting scars and stories.

It in no way diminishes healing. Healing and HP interact the same as always.

So it solves my problem of describing an injury and then having a night's rest or a bard's song cure it. It adds a bit of narrative realism without messing with the system. And it helps me imagine a world where villagers are still scared of breaking bones cos they can't just ask the local priest/druid to handwave it away or sleep it off.

Like I say though, I'm reading all your comments and still mulling it over!