Reneging EB for Top Tier BB

I did a similar thing but accepted the BB offer before declining my EB return offer. Do not jump for the exits (seriously don't), jump only if you are sure that the BB opportunity would be the perfect exact fit for you that comes around once in a lifetime. But most importantly be sure you are genuinely interested in the work that that BB group does and that you really get along with the people there (imo nothing beats this). For your situation, the question boils down to this: how much better is this top tier BB group's exits compared to my EB and is it so much better that it pushes me to take the risk of recruiting post-offer and maybe not even getting an offer and thus giving up everything I've built over the summer. Another super important thing to bear in mind is that just because a BB group has traditionally good exits, doesn't mean that YOU will be one of them - this very much depends on yourself, group only helps you to get looks across the street and the rest is up to you being a top-bucket analyst. Also remember that BB classes are larger so it would make sense that they seem to place well all the time.

My EB never found out until the day the MD called me into his office to give me a return offer and I told him I would be declining face to face (this is always better so if you do decide to renege, honestly would make the effort to discuss face to face and do it the right way). It was awkward at first but he was surprisingly supportive of me and wished me good luck so doing things the right way goes a LONG way and you don't want to end the relationships you built over the summer in a bad way.

If you are sure you want to recruit after accepting I would say be extremely careful who you network with because the only reason my EB didn't find out I was recruiting was because I only networked with school alumni who were my personal friends andwould have less of an incentive to snake me out - at some point though you need to have a certain amount of trust/faith that they will be on your side. Be careful when speaking to senior/junior bankers alike and articulate extremely well why you want to switch because they don't want you to be there just because you think they have better exits (I imagine this to be a 1st class ticket to getting ratted out to your other bank) - and whatever you do, do not badmouth your EB.

tldr: If I were you, I probably wouldn't attempt this simply because if you say this BB group has good exits, I'm assuming it's extremely competitive to get into and you may not even get an offer there. And unless your EB restricts your exits to oblivion, there is really no added benefit to jumping ship for marginally better exits (pretty much all EBs get great looks across the street anyway). Just focus on being a top-bucket analyst at your EB and make genuine connections there. If you have that at your EB and they don't restrict exits, don't leave - trust me, your life will be much better as a result.