I know the feeling for sure - this year we seemed to end up about where our robot deserved to be, but 2702 has ended at the bottom of the standings some years when our robot was far better than that.
One mildly accurate evaluation of a given team's strength is OPR. You could look at the average OPR of your alliance partners, average OPR of your opponents, and see how those averages compare with the OPR distribution at the actual regional. Actually, I could probably throw that kind of average calculation into OPRNet in about an hour.
Example: at Waterloo this weekend, we have 33 opponents and 22 alliance members. If our alliance partners had an average OPR of 5.5 and our opponents had an OPR of 11, we could say we had a tough schedule.
There's a bunch of ways that people analyze schedule difficulty in pro sports. Here's a good starting point:
http://en.wikipedia.org/wiki/Strength_of_schedule