H1B Extension Vs L1A Visa

[venkitta]

Hi

Here is my background:

Currently, I'm in India (returned to India on 2013). My H1 got expired in 2015(EB2 filed, I-140 approved). I understand that, Since my I-140 approved and the H1 was valid till 2015, it can be tried upon under cap exempt

My company is asking me to choose between L1A or H1B extension.

I need to know the pros and cons of each VISA.

Also, If I get L1A, can I work for a customer at client location or should I work only at the employer's location?

Thanks in advance for your help