The biggest component of Sagarin's rating is SOS. The whole reason it was started in the first place was to compare teams with unequal schedules. The reason you think Sagarin is unreliable is actually wht makes it the most reliable, lol.
I know it's hard to convince yourself that your gut feeling is better than math than statistics;
it's human nature. But it's also the reason why 1-800-BETS-OFF exists. Because people think their intuition or eye test is better when in reality it's impossible.
The Sagarin rating is nothing more than a predictor of wins against a team lower in the ranking. Basically it uses math--not gut feeling--to say that a team rated 64 will with high confidence beat a team rated 78 or whatever. And its the best one out there by a mile and a half...it does a scary good job. Look up the studies that have been done on results. It scores orders of magnitude better than any other poll out there over time.
And the SOS (which is also math-based) is fluid each week. Which is to say that Sagarin ratings are new after each set of games and don't let previous rankings influence current results (hint, hint, AP and coaches polls..).
Massey is another solid model that does really well but not as well as Sagarin, and Massey's composite rankings are fun as well although that one includes 2 human polls to appease dumb people. Massey (also formulary with no human bias) ranks SDSU 60 this week.