We used the VIP check-in service last week. There was no line in the VIP lounge that morning so we got helped right away. I wouldn't say that the woman who helped us was friendly but she got the job done. When we didn't like the location of our preassigned room she listened to our preferences and found a suitable room for us. She gave us a line pass for the restaurants and had us on our way pretty quickly.
The biggest advantages of the VIP service were not having to wait in line and being able to get into our room right away on a Sunday morning. On previous stays when we arrived in the morning we generally hadn't able to get into our room until sometime later. Since I place a high value on being able to get into the room upon arrival I would use this service again.
We had a good stay in a room with decent air conditioning and a comfortable bed. This was in the Carson (South) Tower as no upgrades were available but we were satisfied with it. To top it all off I got a Royal Flush on a video poker machine in their casino.