Welcome to the site and good first cook!
I'm uh... going to go against the grain here and suppose that the sausages were tasty but might have been a little dry. I'm just going by the amount or shrinkage and comparing them to what I'm accustomed to. Long before the brats I cook shrink that much, they've hit 160°F and that's when I pull them off the grill. I check with a Taylor Weekend Warrior. ($15.50 on Amazon) Or you can spend the Big Bucks for a Thermapen (but if you do, look for an open box sale and save a couple.)
I also throw a couple pieces of hickory on the coals when I put the sausages on for a nice smoky flavor. It will flare up when you open the lid but will smoke with the lid closed.