An alternative would be 24 to 31 (4 lanes, nice and flat), to Highway 6. (2 lanes, nice and flat), to 15 to Goshen. This would probably be a little faster.
We have driven 15 from Wabash to Goshen several times. Very nice comfortable country style driving. Let's you "smell the cornfields" as you drive by!
If you want to go faster, stay on 31 till you get to 20 east. Take 20 to 33 and then turn South to Goshen. It just depends upon if you want the country route or the fast-track route.
Either route is good.The distance will be about the same, by about 10 - 15 miles.