L1 to H1 COS Vs consular process

[rino]

Hi,

Currently I am working on L1 with company A ; I am trying to find out some company B who would file an H1 for me. I need help in understanding following things.

1. What's better COS or consular process? pros and cons of each
2. If company B files the H1 with COS now (before oct 2011), does my status get changed immediately or only on Oct 2011?