@Rudramati,
Mine is a direct hire model and have been working for this employer for the last 5 years.
I heard that if you are working under EVC(employer-vendor-client) or EC(Employer-client) style , then all you have to do is prepare 'proper documentation', I guess that shows clear understanding of the projects you have done. Its better to consult with Lawyer in that case to prepare proper documents.If the employer is genuine, if the project you are doing is genuine and the client is genuine, then there will not be any problem, I guess. So proper documentation is the key before taking any risk of going to H1B stamping to Canada or anywhere.
My suggestion is "If you are confident about your documents, go ahead, it might takes longer but you will definitely get it. OW never ever try to take this stupid risk." I still remember my lawyer saying, "Donot go to Canada or else just for H1B stamping reason, US embassy feel irritated as you came to Canada just for H1B stamping and no other reason. ", so I donot know, I wanted to get it done soon and I decided to go CA. So, sometimes we have to take risk to get things done.