There's no doubt that Fred has produced far better results than Fran has (and the Big XII is no cakewalk, either) in the same time period, but it's dangerous to look at overall numbers in a vacuum..
Iowa's stats for the 5 years prior to Fran, and since, break down to 50% overall and 40.6% in conference before Fran. 54.9% overall and 42.8% in conference since, which doesn't look like much of an improvement on the surface.
But the last 3 years, the numbers are 62.5% overall (60-36) and 50% even in conference (24-24). The improvement is more obvious when you consider it took Fran a couple years to recruit and get some of the Lickstink out of CHA and look at the results when he wasn't more or less hamstrung with Lick's players.
For comparison's sake, Tom Davis was 65.7% overall at Iowa, and 54.3% overall in conference. But yeah, Davis obviously inherited a far better situation than Fran did, when look at overall percentages. So I don't think Fran is very far from Tom Davis results.
If this is the ceiling under Fran, am I happy with that? NIT's and a "first four" loss? Hardly. But it's a gross understatement to say that we're in better hands with Fran then with his predecessor. As I've said before, I think Fran has done enough to this point to warrant at least another year or two.