Kennedys:
THey are real light but they have an upper that seems to give guys on my team blisters on the side of thier feet.
THe raised spike wells are not confortable for me at all. I don't think they are very suited for longer races, and the wells tend to slip if you put smaller spikes in. The inside configuration tends to give people foot pains unless you run on your toes the entire race.
The plastic nubs wear out real fast as well as the cushioning, not that there is much anyway. The fit to mee seemed wide, I have narrow feet and I had to tighen the laces a lot, I think its because of nike's tendency to have 'cushy' heels.
Ventulus (plus):
Lightest distance shoe out there. Well except for the mangostin...can't find those anywhere really...except the adidas outlet in this town hahahaha..
THe spikes are really suited to 5 or 10 thousand meters, and yes they are a tad long, but nothing that will really bother you or get you d'qed. The two spikes in the back made it easy for me to run tall but not on my tiptoes like i felt i had to with the kennedy's
The upper is much more confortable then the kennedy's but again the heel tends to be wide for me. The spikes last surpirsingly long (for 99$ they better), just don't wear them on pavement even walking to the track.
The plus have an open mesh upper for steeple, i don't know how well the spikes would work for steeple, I'll stick with the adistar's for that event.