28mm 1.8g for a fun portrait lens instead of 24-105mm?

Backstory...I have a D600 and 85mm 1.8g and 50mm 1.8g.  I primarily shoot my wife, son and friends.  I've read where the 28mm offers unique perspective in the portrait shots and I'm reallly interested in that since I'm shooting my 9 month old most of th time.  I only see myslef staying mainly in portraiture in the near future and mayble dabble in street/macro photography.  I just got the 24-120mm f4 with the $300 rebate and I'm beginning to wonder if I should have just spent the money on a wide angle prime (28mm 1.8g) and saved the rest for the 105mm micro one day.

I bought the 24-120mm f4 because of the price and because I thought a mid-range zoom would be beneficial in the long run.  I did a ton of research on here about the quality of the lens, but after receiving it and shooting some, I'm having serious second thoughts.  I love my 85 and 50 primes and think that I would also love the 28mm prime.  I do travel some, but realized that I would be fine with just using the other primes when traveling.  When shooting on the weekends, I tend to setup the situation so I don't feel I would need a zoom.

So I was hoping I could get some advice on how to proceed.  I really like the fast primes since I do shoot in low light often at home. I'm worried that my 24 -105 isn't going to live up to my expectations.  Do I just keep the 24 - 105 or sell it for a 28mm 1.8g or sigma 35mm 1.4?

THANK YOU IN ADVANCE!