Before I returned the Nikon D90 to my brother, I brought the boys to a nearby park and did some shooting again. Boy, it was hot and too tiring. I hate our weather now and I remembered it wasn’t so hot when I was younger! (or is it I have higher body heat now that I am bigger and fatter?)
Also, I realised it is not as easy to do photography with young little boys, which still requires a lot of attention, in terms of feeding, carrying them. So I have decided a heavy camera like that is definitely not for me. No time to focus and care for the expensive camera as I need to place my full attention to the boys during outing.
Might consider a 4/3 later, if budget permits.