Help me choose! topic

I had a Galaxy s2 and now... I have a Google Nexus 4 love it but it's on HSPA + for AT&T and I hate that about it..

I have a choice..

Come to the Moto X or Goto the Samsung Galaxy S4..

Can anyone tell me about their experience with the S4 what you love and hate about it what someone learns after buying it, if you could would you buy it again?