I hired a layer Mao-sen Yieh in September and paid him , but he didn't do much work except gave me some sample letters and sample cover letter. I prepared everything by myself and he couldn't even have time to look at it and submitted before deadline.So I got my materials back and filed it by myself.After I got the ITD, I asked him for advice, he said I had a weak case but he said I have great case at first time( I applied NIW). I was so disappointed with him and hire another layer Augustine Huang in Zhang Associates. Huang said I had very strong case and even qualify for EB1-a. He encouraged me then we hired him and he did great job.
Although we spent more money but it worth it.