I am, in trial mode, but I'm actually doing the recipes formulation in both Brewtarget and Brewer's Friend. So far, I'm seeing small differences in ingredient calculations, leading to higher OG and large differences in IBU calcs (60.7 in brewtarget vs 86.29 in Brewer's Friend, which is larger than 18% (I have brewtarget configured for 82% utilization, but that's nearly 35% different)). The volumes are higher in Brewer's Friend as well, and I have those very dialed in with Brewtarget. I'm not really sure why the volumes would be different though, unless grain absorption is determined differently. Anyway, it's a nice website, so I may use it, at least for a couple of recipes but if the volumes, gravity and IBU calculations are off, it's not going to be very useful.