H1B Stamping in Mexico city, Mexico

[Siddu]

Hello,

My H1B visa stamping expired in oct/ 2008. I have changed XXX company in Feb/2008 (XXX company 1st I-797 was from 2008 to 2010 and now 2nd I-797 valid from 2011 to 2013) continuing with same XXX company having over 60K employee's in US & over 500K in global.

I'm going to Mexico for business trip and same time planning to get visa stamp in Mexico city, not with family.

I cam to know that I can re enter with new I94 ( valid 2013) in automatic revalidation, please let me know what kind of risk I will have, which is better option just re enter with I94 or with visa stamp.

ASC can able to guide me? how long visa processing take time, days? or weeks? any one got stamp in Mexico city please share.

I got 140 approved, is this will help me? also I have properties in US..

Thanks,