One big challenge is slowness of process–certainly no surprise at all which is why my civil society colleagues asked that the contingency plans for this be announced ahead of time by the IEBC (electoral commission). Poll openings at 8-10am appear common in Nairobi rather than scheduled 6am–again no surprise given the logistics involved. It certainly appears that in most cases a paper rather than electronic poll book is in use. Further it appears that complete absence of working electronic BVR for voter identification is common. Some polling streams never received hardware at all; others received too little or found it unusable for whatever reason.
Wholly manual voting then is normal, even though the voter registration was truncated to provide for the use of BVR. Given that the voting is inevitably slow and the turnout is huge, I heard from one fellow observer of polling station workers just taking down names of people who presented IDs and allowing them to vote because it would take too long to try to find and check off names on the paper lists.
The voters are being in general extremely patient with hours of pre-dawn queuing and waiting in hot sun. Ordinary Kenyans in Nairobi certainly are demonstrating both peace and a commitment to the voting process itself.
The unexpected problem, to me and people I have spoken with, is that the ballot boxes were getting close to full with only a relatively small percentage of voters having voted. Presiding officers indicated no backup capacity, but were shaking the boxes to settle the cast ballots..