Psychometric information on IPIP representation of NEO facets
The table found at your second link (comparing the IPIP NEO and official NEO) seems to have come from this paper by Goldberg (1999): http://projects.ori.org/lrg/PDFs_papers/A%20broad-bandwidth%20inventory.pdf. This paper discusses the generation of the IPIP items as well as the sample it was originally administered in. A 2006 paper (also by Goldberg) provides additional information on IPIP development: 

Unfortunately, I was unable to locate information on the factor structure of the IPIP NEO 30 facet form, only the IPIP 50-item FFM (Ehrhart, Roesch, Ehrhart, &amp; Kilian, 2008), which seems to be a different measure (http://ipip.ori.org/newFinding_Labeling_IPIP_Scales.htm). 

Ehrhart, K. H., Roesch, S. C., Ehrhart, M. G., &amp; Kilian, B. (2008). A test of the factor structure equivalence of the 50-Item IPIP Five-Factor Model Measure across gender and ethnic groups. Journal of Personality Assessment, 90(5), 507–516.

Goldberg, L. A., Johnson, J. A., Hogan, R. , Ashton, M. C., Cloninger, &amp; Gough, H. G. (2006). The international personality item pool and the future of public-domain personality measures. Journal of Research in Personality, 40, 84–96.