It's bad IMO. The large amount of interiors made lighting the mission take about 10-15 seconds, and I lagged for a second when I spawned. Most of the interiors are really pointless. The actual track is very long and flat. Flat as in not just actually flat, but very simple. It's either you go straight or you make a 90 degree turn. I imagine it takes over 15 minutes to actually finish a lap. The only time the track is not actually flat is at the jump. With which vehicle do you expect to actually make that? The turismo couldn't make it, so what vehicle can? You also have no indication of which way is the right way, or does it not matter? There is also the matter of the terrain which is flat, except when there are hills just jetting out of the ground like they were make by an amateur map maker.
Overall I give it a 5/10. Only reason there is a 5 is because considering how long it is and how many interiors there are, you had to put some effort into it.