Without trying to kick-start the value of Iupati debate, think about this...
All season long, he has graded out well. His whole career has graded well. Leading up to the Senior Bowl, he was projected as the #1 OG & possibly the #4 OT available. He killed it in practice. Then, after a poor Senior Bowl game, he's over rated?
It sounds strangely familiar to what happened to this other guy Chadman remembers...a guy that had an outstanding college career, was rated as a sure-fire 1st round pick leading up to the Senior Bowl, but had a below-par game at the Senior Bowl & subsequently dropped in the rankings into the 2nd round....and was later picked by the Pittsburgh Steelers...and became their starting LOLB the next year...you know him right? LaMarr Woodley? Remember him?
Don't judge a player based on one game. Iupati was rated that high for a reason leading up to the Senior Bowl.