Every finish line is a bit different depending on the layout of the location but they're all similar from what we saw during the week on TV. In Steamboat the VIP tent took up one side of the final 50 meters or so of the finishing straight going right up to the finish line. Inside the tent were a number of food and drink stations as well as flat-screen TVs. Before the live coverage started on Versus (now NBC Sports Channel) the TVs were hooked up to the RadioShack Tour Tracker app so everybody in the tent could keep track of where the race was. We were able to relax out of the sun, have some food and drink, and pick up some swag from the sponsors.
We were also able to come and go as we pleased so we left and wandered through the festival to get some souvenirs (Jelly Belly was giving out replicas of team musettes if you signed up for their mailing list) and we got Phil Liggett's autograph behind the podium (we just missed Paul Sherwen but we got a nice picture of him). With an hour or so to go before the expected finish, people in the VIP tent started staking out spots against the ad boards so I moved over to claim a spot with a good view of both the finish and the winners podium, we were probably 15-20 meters from the finish right on the boards. About that time some cycling blogger who runs this site came and introduced herself to us ;). When the race came into town and flew by us, my wife was taking video and as they went by (Elia Viviani for the win!) she shouted, "I'm not really sure what just happened but it was cool!". Afterwards we were able to stay where we were and watch the jersey presentation across the way, though they opened up the ad boards so that people could fill the street to get a better view.
I'm glad we did it but its not something I found to be really necessary if you're willing to put in the time. Had we shown up at 12:30 without VIP tickets we could have gotten the same view we had but on the other side of the street in the open viewing area. The difference is that one of us would have had to stay there for the 3+ hours before the race finished, so instead of being able to wander through the festival together we would have had to do it individually while the other one saved our spot. It also would have been in the direct blazing sun instead of under tents (and since my wife was recovering from an illness earlier in the week, that would have really sucked). Plus the addition of free food and drink were nice as well. Nothing spectacular but the water and sports drinks were great with the heat (alcoholic drinks are also available for those interested). We "saved" our spot at the rail for the last hour or so, but honestly we could have walked up to the rail literally on the finish line a few minutes before the race got there, though this might have been due to the trees blocking the view of the stage from that angle. Either way, inside the VIP area, we could have found a decent spot minutes before the finish, which certainly wasn't possible on the other side of the street.
We stayed in town for the start the next morning but did not buy VIP tickets for that one. Based on what we saw at the start, at least in Steamboat, that seemed to be a good choice. The VIP tent was set up similar to the finish line but it was on the other side of the road from the sign-in stage. We showed up early enough (about 8:30 and the start was 10:30 IIRC) that they were still putting together the start line arch and barriers when we got there. We were just wandering around and suddenly realized that the barrier in front of us was marking the path the riders would take to get to/from the sign-in stage [Autograph Alley]. We decided rather that tour the team buses, to stay there and wait and sure enough as riders started showing up they walked right in front of us. Most of them stopping to sign autographs. We got 40+ autographs that morning, including all the big names of the race other than Evans, Basso, and Gesink. Bob Roll stopped by as well. A couple of Karen's pictures of fans getting autographs from last year include us in the photo. If we had been in the VIP tent on the other side of the road we wouldn't have gotten nearly as many autographs as only some of the riders made the effort to cross the road to sign autographs for the people standing on that side.