I-130 sent out today

[elcupacabras]

I wouldnt take the dates on USCIS website as gospel. Going by people's experiences it appears it will take approx 135days from your I-129F receipt to its approval.
Use this link to help you see the current average approval times.
http://www.visajourney.com/timeline/stats.php?cfl=

 

[elcupacabras]

Pawhut. IR1 and K3 are both spousal visas. The IR1 visa holder will immediately become a permanent resident upon entry, whereas the K3 holder will need to go through AOS. As far as Im aware, the IR1 takes a little longer and has the possibility of getting 'stuck' if procedures change. Filing the I-129F to make an IR1 into a K3 protects such a thing from happening.