Interesting question. I think my personal opinion is that it doesn't really matter.

I feel like the main problem with rapid job moves is that other employers might not want to hire you, because they are worried that you will leave quickly.

But that's often a secondary factor in hiring, which can count against candidates but is usually not a deal breaker if other things look good - most law firms aren't charities, so the commercials have to be ok for them, even with the risk that a partner may leave in a few years.

Clients don't really care very often, if they are loyal enough to follow you from place to place and your practice is fairly independent.

Your associates might lose out, but if they're super loyal and the partner has clout, then they can also tag along.

Finally, if you consider that most lawyers are technically independent advocates on retainer for a firm, then in a way the more often they move, the better.

And there are certain advantages also for individual partners who move often, I imagine. 1. You don't get as bored. 2. You benefit from new client exposure and networks at new workplaces. 3. You may learn new skills from different seniors or colleagues. 4. You don't get complacent in a single way of doing things, so it keeps you on your toes. 5. You develop a stronger, more independent practice.

So, all in all, I understand why partners would move jobs often and wouldn't begrudge them regular moves...