Donna, I will probably wait until at least 20 miles - even though 6 doesn't sound like much in the context of a marathon, it can be a hell of a long way if you're knackered, so I don't want to blow all the good work by quickening to early. Hee hee listen to us - I'll be happy to get round in under 4hrs. 3.45 or better would be a real bonus.
Swerve, you're a man with the same plan as me. I run 3 times a week - long, tempo and speed, and it works great for me. I just can't muster up the motivation to run more than this, and my body seems not to like it either. But Donna, as you say, it's a personal thing, and if you're coping with the mileage you're doing then good for you.