Let me know the next time you see Asbel Kiprop, Eliud Kipchoge or Evan Jager wearing a pair of those.
In fact, running on Vibrams on sand or grass is very similar to using cleats on the track. I say this as a ex-competitive runner.
No, they aren't. Track spikes maybe, marathon shoes definitely not.
Have a look at the Adidas Adizero Adios [1], a shoe that Kimetto ran in to set the world record. It has a heel of 26.7 mm, and a heel to toe drop of 9.3 mm, and is quite stiff. A Vibram has maybe 4 mm of rubber, no drop, and is very floppy.
Yes, they are less cushioned than the average running shoe, but they are very far removed from Vibrams. I say this as an amateur runner, but I regularly run 100+ mile weeks.
[1] http://www.runnersworld.com/shoe/adidas-adizero-adios-3-mens
I'll just point out that I agree with Vybarr about what the reasons to run are and why one should do it. I really hated running until I tried those shoes (very minimal shoes in general, nothing special about Vibrams specifically unless you are out in nature on very uneven terrain and need separate toes to help balance), now it is a joyful experience that I look forward to. There is a reason that owners got so excited about those things that it started to annoy people. I'll stand by my statement, and if I ever feel the need to compete at long distance then I'll wear whatever shoes get that job done the best.
http://www.all-athletics.com/files/imagecache/photos_big/pho...
