General rule of thumb when assessing a law firm's quality is to look at the bench strength of their 'mainline' (rank-and-file) partners. These are the partners that are actually doing the work / cultivating the client relationships actively on a day to day basis.

Are the mainline partners notable? Are they known for high value or high profile deals and cases that are commonly featured in legal industry publication? Do they have notable clients? Do they have steady stream of clients? Or are they unknowns? (posting on linkedin incessantly all day doesn't count).

Not the Consultants or Senior Partners or Senior Consultants or Consultant Emeritus etc etc. Firms sometimes pad their roster with these distinguished names from the legal industry to lend an aura of respectability and gravitas. But in reality, the presence of these names may not really translate to much in terms of client relationships and actual work.