Mike,
THANKS for your feedback,,, you are right this is what the spirit of the Beta is and please keep the feedback coming !
WRT to lab not completing,, trouble shooting this is hard,,, I will be posting some guidelines on how to collect log information when taking a lab (shortly) so we can present it to our R&D team.. (we just run the browser in Console mode and copy / paste the error messages)
PM if you have any questions,,
thanks again
Pablo