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 have a good level of confidence in the IFLR1000s ratings. I use it for outsourcing and as to whether I should accept a legal opinion issued from a law firm in a country I am not familiar with.
Middle East-headquartered bank