I find the IFLR1000 an up-to-date and credible source for selecting and sourcing new legal firms in a new business area or country, and to compare legal firms capabilities in different practices.
I find the tiered rankings particularly useful when benchmarking and comparing between existing legal firms, plus looking at unfamiliar legal practices or locations.
I refer to the IFLR1000 especially with respect to jurisdictions I have no knowledge about. The main reasons: to find a good firm or confirm standing of a firm recommended by someone else.
I usually use the IFLR1000 in connection with a need to engage a local counsel on an M&A deal.
Corporate M&A lawyer
Listed international pharmaceutical company