I did an 100k ultra last weekend and you can definetly feel you've done 50 in your legs but I did Enjoiy it to be fair it's a bit like the last six miles in the marathon

I'm a big fan of staggered starts, partly because I tend to get impatient hanging around for a massed start - I find myself raring to go as soon as I've registered. This may be a consequence of being so slow - I know that for any 50 I'll be walking for several hours in the dark, and for a winter 30 or 40 at least some, so I feel that half an hour of daylight spent standing around at the start is wasted. One of my favourite challenge events is the Coventry Way (non-LDWA), for which a staggered start is necessary because there's a stile a few hundred yards into the course. I know that at my speed I'll either be starting or finishing in the dark, and as the first few miles are easier walking than the last few it makes more sense to start early. Fortunately I've been able to get a lift with one of the organisers the last couple of times, which means I'm there when they're just setting up and can start immediately (I know my pace well enough to guarantee I won't get to the first checkpoint before it opens!). Starting at 5am means I get to enjoy the birdsong, see the sunrise, get 5-6 miles on the clock before everyone starts overtaking me - and finish while it's still light.

I've never done a 100km (there are far fewer of them in the calendar than there are 50s), but I'm hoping to do the Wealden Waters this year. I failed to finish the only 100 miler I've entered to date (although I got past the 100km mark), and found the step up from a 50 a bit of a shock. I'd view a 100km as a useful intermediate step, so I can start a 100 miler without it being twice as long as any event I've completed before. I've sometimes wondered why there aren't any 70 or 80 mile events, as another stepping stone between 50s and 100s. Do such distances require significantly more effort to organise than a 50, or is it just that people figure if you're going to walk as far as 80 miles, you might as well go the whole hog and make it 100?

Just wondered if anyone else struggles with 100k's these days. I used to love these but then found the extra 12 miles from a 50 as pointless as this would mean finishing on the sunday morning rather than the sat night, and then a 'jet lag effect' for the next few days - I deliberately avoid them now. The 100 miler is different as it't the flagship event but whilst I am working full time I find the effect of 100k on my body disproportionately more than a 50.....anyone else found this?
Also does anyone else think it is a shame that more starts aren't staggered (even slightly)? I just find mass starts a bit of a bun fight, everyone trying to check in at the same time, jossling for position for the first few miles once it kicks off, queues if there's a stile and ......(I'm going to sound really antisocial here), but I do like to occasionally hear the sounds of the countryside, the birds, the trees and often seem to be walking at the same pace as someone who chats away loudly to their companion without coming up for air.....and I cannot tune out their conversation......and when this goes on for miles and I can't shake em off, it gets waring :-)
A staggered start may well prevent this?