dloui ,i havent had an epi so cant say but ive heard it slows down your labor,and as for me usually when i am able to get one it is when it is the most painful,if you just hold on from that point,usually its time to push and bang ..it goes so fast ..for me anyways,i really believe if i got one it would take longer,maybe somehow my body feels the pain and says(o.k. enough of this lets get this over)
My first birth was better (sort of ) than my second because i had to get my water broken by the doctor bcause it was taking too long and that was way worse than it happening naturally! And relaxing through the contractions helps alot,thats why i like to prepare mentally,because i believe it helps the pain to relax into it,for me anyhow :)