There could be several factors that can make the I-130 process longer (i.e. Depending what Consulate you go through, etc.) . I just got our I-130 and I-129F (K3) approved on 02-28-07; and the K3 package is been forwarded to NVC for processing (which still can take a couple of months to be sent to the Rio Consulate).
From what I read and researched, K3 was supposed to be quicker, however, both were approved at the same time! So since the I-130 is been held here in the US, and the K3 is been forwarded to the RIO consulate, I will continue with that route instead of filing for the I-130 to be transferred to Rio and can delay the whole process process.
I contacted the Rio consulate, they said that which ever petition arrives first, they will process that one. Unless, we contact them and ask them to wait for the I-130 petition. Contact the US consulate where you are supposed to do your interview to find out the processing time. Rio consulate is a max. of 45 days from the time they receive the package from NVC for example.
P.S. Rio consulate = US Consulate in Rio
Again, if you are interested in filing for the K3, people usually send it out right after receiving the NOA1 for the I-130 petition. That's the only way to file a K3 petition is with the NOA1 for the I-130!