Running

Yes, very. I'm always interested in this kind of stuff. But IIRC didn't you mention a few pages back that you have a fair bit of ultra experience (Al Andalus?)? My training is motivated in large part by the worry that I have zero experience and although I have some (LD-Tri) base fitness, I lack running miles. I've still never run more than a marathon in one go.

I've done a little bit of ultra as I keep getting run over and breaking wrists, so can't ride - Hereward, Gin Pit double mara, UKA 100km, a couple of London to Brightons and Enduroman 100 miler. Got PF doing the last one (which is why I didn't end up doing AA) and haven't run further than 30 miles since. Probably looking at 24 hours for the TP100.

Ultra's a headgame, and pacing is pretty key - it's just hard to keep going slow, and to get your head around the fact that you have to keep going that slow for 10, 15, 20 hours. It can be horribly depressing finishing a marathon, really hurting, and realising you have another 3 marathons to go.

You're doing great miles, but I don't think many people will be doing that many heavy weeks - particularly if your body's not used to it (this is way harder on the body than IM training).