Took several classes there and really enjoyed it. Smaller class sizes, rooms to study in, smaller testing center, etc.

Driving: Depends on when the class is. Normally 40-60 minutes one-way depending on traffic. BYU students just scan their ID outside the parking lot to park in the SL center parking. Plan maybe around 2-2.5 hrs in just commuting roundtrip. Keep in mind that parking gets weird with the Delta center being so close especially during NBA season.

Trax: 60-80 minutes one-way depending on where/waiting for UVX. Getting to North Salt Lake station on Frontrunner is nice because they have eduroam to do homework on the train. The walk to the SL center takes about 5-10 minutes from the station. Plan around 3-4 hrs in just commuting roundtrip. Just be punctual for Frontrunner because they won't wait for you. Miss it and you could be waiting another hour or more.

I recommend scheduling as many SL center classes on one day WITHOUT Provo classes. They typically offer classes that are once a week, so that way you only have to come up to SL once a week. Trying to have classes on both campuses can be tough unless you have several hours in between to either drive/catch the train.

Hope this helps