I can argue both ways:
Pros:
for employee:
-ac21=>employee can move around. spouse and dependents can use their EADs to start working.
-employee can start their own business if they choose to.
-promotions do not require new perm.
for employer:
-can still fire the employee even if the sponsorship is for a permanent position. This may mean big corps (that traditionally are reluctant to sponsor) might be actually willing to do so. This could actually spell doom for the staffing firms.
-employers know upfront that the employee is mobile. This lets them be more choosy as to who to sponsor for GC. If it looks like the employee is not 100% loyal to the employer, the latter can say no sponsorship for that particular employee.
-Employer has the choice to wait for upto 5 years and monitor the employee performance and then only decide the perm thing. Keeps the employee on the toe and could provide boost to the productivity.
Cons:
employee
-increased competition because the labor pool now includes USC, GCs and all other EAD holders
-still need to find employment in similar position.
-no use of pd whatsoever.
-clogged up uscis system; hence increased delays in obtaining any docs from them.
-nobody would perhaps choose CP.
-employer can delay the GC process as much as 5 years.
Employer:
-doom for staffing firms.
-GC process investment is not recouped.
There could be more reasons added to both the lists.
backroady said:
If you are allowed to file I-485 before your priority date is current then of what significance is the priority date?
Why have a priority date? Might as well throw the process out the window and give green cards to everyone.