[pct-l] Crampons

[The Incredible Bulk]

I am going to need to use crampons in two weeks.  I was looking at Yaktrak and Kahtoola crampons since I do not need full-blown crampons to hike into the Grand Canyon.  I will be using the crampons with Merrill Chameleon shoes.   Since there isn't much of an instep with these shoes, instep crampons are out of the question.  
 
Is one better than the other for my purpose?  I understand there will be ice on the upper partions of Bright Angel Trail, and possibly snow.  

Thanks!
-- 
Tom 
The Incredible Bulk