My recent two deposits an hr ago confirmed and showed in my account in about one hr. nice.I think it something also to do with where you are transferring coins from. I noticed if I use some exchanges or wallets , it's slower than others. One exchange I use transfers to sr address in under one hr. you can try adding more to yur transaction fee for faster transactions. As for some SR accounts being slower than others for deposits , sounds strange. It would imply that accounts are grouped up and divided in some way resulting in a group of accounts being slower to access the resources on the servers.