Two observations on Ibanez:

1.) In the Ibanez case, it wasn't simply a matter that assignments were filed long after the actual assignment transactions.  The assignments in question were filed after the actual foreclosure sale.

2.) It's my understanding that the mortgage in question in the Ibanez case was not a MERS mortgage, and that the after the fact assignment filings were generated from assignments in blank held by US Bank, not assginments that were created from scratch based on a MERS assignment chain. Albrt, a guest poster on the Calculated Risk blog who often posts indepth analysis of important housing-related legal cases, had this to say about Ibanez:

This case also demonstrates that recorded title documents can get plenty screwed up without any help from a third party like MERS...  In fact, Judge Long [in the Ibanez ruling] seemed to suggest in two footnotes that the banks would have had an easier time in this case if they had used MERS.

Again in my opinion, we see another problem that MERS is blamed for-- the fact that mortgage assignments are not filed in the public record at the time of the actual  transfer-- is not a MERS-specific issue, but occurs on both MERS and non-MERS mortgages, becasue banks simply don't want to pay filing fees several times over on one mortgage and will go to some trouble to avoid them, MERS or no MERS.  It's just that keeping track of the assignments is a lot more efficient with MERS, because they don't have to store and keep track of a bunch of paperwork.