Entirely depends on the terrain/weather conditions, mandatory kitlist, how long you expect to run, how much fluid/nutrition you'll expect to want during the race. Number of checkpoints/dropbag facilities. Personally, I've done 50k's before with nothing apart from water at checkpoints. Even with that advice in mind, you won't know how comfortable any model is until you've actually tried it on, so go into a shop and try a few on.
Good return TT. Have followed the developments with interest.
Excellent parkrunning RS.
After my nippy 400s, thought I'd give a flat parkrun a blast to see where I was - got tripped in the first lap, stayed on my feet, but rythym was gone, and struggled to regain my pace for another half lap, pushed on in last lap to overtake a few, and got 18.20. A bit disappointed. so did a bit more to give me 9M total at 7.00s
Very nippy paces going around. Not sure mine can compete but last night was 10x400 with 400m jog - not sure what paces I was doing in the fast bits, but finished the session (5M in 32.30) and the jogs were SLOW.
Short double for me today - 30min easy before breaky and a hilly lunchtime 5M.