Good job as there were a fair few nics running at 100MB rather than 1GB causing a few issues.
The following script will list each host and there nics and speeds....
$VMhosts = Get-VMHost | Get-View
Foreach ($vmhost in $vmhosts)
$pnic = 0
$Speed = $VMhost.Config.Network.Pnic[$pnic].LinkSpeed.SpeedMb
Write "Pnic$pnic $Speed"
Until ($pnic -eq ($VMhost.Config.Network.Pnic.Length))