I-140 experience letter - premium processing - urgent

[aaa06]

Has People who submitted exp letters from ex-collegues for I-140,have got their I-140 approved successfully?
This will greatly help me to rest in peace.

Because out of 5 years of experience,for one year of work experience,I dont have exp letter from my previous employer.
Instead I have experience letter from my ex-collegue.
Is it ok?