From Bankrate.com Q/A: http://www.bankrate.com/finance/c...-score.asp
This example did not fully reveal the full impact of Balance Transfer (BT). When I applied for the NFCU credit card to take advantage of their no-fee 0% BT: I was hit by (1) hard inquiry (pull) for application, (2) second hard inquiry for credit line increase, and (3) increase in debt-to-credit (credit utilization) ratio from $19K of the $20K credit line. It was a significant reduction in my FICO score, which should recover after the one-year 0% offer expires and is paid off.
Thus, in general, one will suffer in FICO in taking advantage of the 0% BT (even without transaction fee) in terms of hard inquiry and debit-to-credit ratio. There is no free lunch in this world, evrything is a trade-off.