My 2 cents here ...
I used MB for more than 15 years now. CIMB for about 3 years now.
I find CIMB, surprisingly, better than MB (I have a biased view of CIMB, it being Bank Bumi in the past). Online help from CIMB is a lot faster than MB and also with successful closure of your issue. Feel like a black hole with MB's online help.
MB is notoriously slow with their inter bank transfer, using the BNM allowed duration to their max.
MB's card section is also not up to my expectation requiring me to contact them to close up unfinished items.
Maybe MB is just too big and internal work flow, staff dedication, etc suffer.
Cheerio.
Maybank vs CIMB, which one offers the best service?