Originally posted by jigesh
Let me give you some more background and my perception of the situation (beware! I am not a legal/paralegal professional).
I remember well that INS used to allow CP and AOS without nullifying I-485 if someone later chose CP (via I-824). Many applicants during I-140 would prefer AOS and then go for AC-I140 (attorney certified I-140)/ CP if the consulate allowed (there by avoiding I-824 instead of doing vice versa and then filing I-824). Later, INS issued a memo (as shown in the memo of the link in my preious post) where, in order to reduce processing overheads, they chose to consider I-485 abandoned if I-824 was filed. However, there's a catch: Suppose you filed I-485 for yourself, your wife and kid (if any); and later if you file I-824 for yourself only, then your I-485 would be deemed as abandoned (since you would be doing CP) but your dependents I-485 would continue as AOS.
CP is good only if you/dependent never were in any violation of visa staus, if the job is secure (no AC21 for CP - ridiculous, isn't it? - but it's a grey area as well), and time is saved only if you filed I-485 not long ago (as I-824 itself may take upto 4-6 months depending upon service center). Better be safe than sorry. Everybody's case, circumstances, and appetite for risk taking are different - so evaluate for yourself.
Best wishes,
Jigesh
Disclaimer: Personal non-legal point of view only.