Big 4 offer vs mid sized offer


I am an experienced hire having worked as a taxman in Kenya for about 4 years after graduation. I secured a job at a mid sized firm that pays really well in comparison to the big 4 (BIG SUPRISE). I have held the job for about 1 year. The pay is really good but theres absolutely no work life balance.I have received an offer with one of the big four but for a much lesser pay (by Kes 50,000) but more attractive benefits. Having recently been married and discovered that i could be with child. I am confused about making the moveā€¦Is it wise to make the move to the big 4 firm in my state? I have been told that despite holdinga degree I will be frustrated till I complete my ACCA? Clearly , 1 year will be gone since it will be tricky to balance work , studying and family. Therefore, I may not grow in the firm. On the other hand the mid sized firm is still coming up with structures and systems. This function had previosly been carried out by the audit function. The mid sized tax practise is young having acquired a partner from one of the big four and still poaching staff from the other big four. I am torn in between carrer , money and a stress free life. May I have your two cents on this.