I had a look at “OOXML is defective by design” and, quite frankly, I am not impressed.

On my surface it is a comparison of OOXML and ODF and it comes out as a landslide victory to ODF. But anyone who has worked with spreadsheet file formats will easily see that it was written by someone who, intentionally or otherwise, is deaf, dumb, and blind to the shortfalls of ODF. And if that is where you start, then what is the point?

For example, OOcalc suffers from exactly the same rounding issue that Excel does. How could it be any different when both are based on floating point numbers? (An in neither case is that a file format issue, but rather an implementation issue.)

For example, the reason that he can happily declare that ODF has backwards compatibility is that he choses a graph sample. And OOcalc’s graphing system has not, shall we say, seen a lot of improvement since the version he tried with.

Don’t complain that “ECMA 376 documents just do not exist” when the same can be said for ODF. As-of version 1.1 of the specification there still seems to no syntax for 2+2.

One could also ask a question such as “how well can legacy spreadsheet files be represented in either format?” A very reasonable question, in my humble opinion, given the number of sheet out there. Of course, since ODF doesn’t actually have non-trivial formulas, we should probably just interpret it with respect to OOcalc’s format. I do not think ODF would fare well here.

Disclaimer: I have not, and I probably will not, read the full OOXML spec.