This is a better decision than simply asking which firm is more prestigious. You are comparing two different career environments: one where you already have trust and responsibility, and another that may offer a stronger brand, broader network, and more standardized development.

The boutique can be better if you are getting unusually strong ownership, exposure to senior clients, and a path you genuinely enjoy. Those benefits are real and can compound quickly. MBB, however, can give you a wider set of future options and a peer group that may be difficult to replicate elsewhere.

I would compare the work you expect to do over the next two years, not the logos. What types of cases will you see? Who will train you? How quickly can you progress? What exits become realistic? And how much do you value the culture you already know?

If MBB clearly advances the career you want, moving can make sense even if you give up some immediate autonomy. But if the boutique is unusually strong for your goals, staying is not automatically the inferior choice. A useful reference is MBB vs boutique and Tier-2 consulting firms if you want to go deeper on that part.

I left a boutique for MBB and the biggest adjustment was definitely less ownership at first. Still worth it for me long term.

How specialized is your boutique? If it is strong in an industry you actually want, that changes the math.

Tbh people underrate having a good team and real responsibility.

MBB is not automatically better for every goal, but the optionality is hard to ignore.