Chris - how does the South Mountain trail compare? About the same? Tough to tell from Google Earth!
Overall, it is definitely tougher than Watchung, but still very runnable. It depends on the trail, but generally there are more rocks and some steeper climbs (nothing too long). But there is some really nice fast single track, which you don't get too much of at Watchung. It is really a great place to run.
I think the route for Sunday is going to be Rahway (white) to Turtleback (orange) and then back on the Lenape (yellow). That should be about 9-10 miles.
Definitely bring something to drink. You can turn back at any time. It is a little trickier than Watchung, as that is a loop so at one point you actually pass pretty close to the cars. This is going to be an out and back trip. It will be about a 2hr. run.
"This is Watchung, not Siberia. Nothing bad will happen"...except bear attacks apparently!
Pretty much the same here... my long-distance road pace is 10 min/mile, 5 mile pace is closer to 9'15. But throw all that out the window when running the trails. I was told to figure on adding maybe 60 to 90 seconds onto your road pace, and that seemed to work out about right for me.