I'm using their sust325 right now. Sust will make you sore if your not used to the faster esters, or if you've never used it before. You should get used to it in time, or you could cut it with the EQ, that should take some of the pain out of it. For sust @ 325mg/ml its actually extremely smooth. I used their sust450 a little while back and that had a little bite to it but nothing I couldn't work through. How close were you to your knee with that injection? An injection should not make you're knee swell up with water. It's more than likely the surrounding muscle around the knee, thats a little swollen from the short esters in the sust. Like I said, cut it with the EQ, or a little test E, and you should be gtg.