tl;dr: It is hard and I'm struggling. But if I had a choice I'll be a stay at home dad all the time.
My company offers 4 weeks of fully paid paternity leave. I'm staying home to help out with the new baby. I thought I'd miss working and I did, for whole two days. I was checking my work email and clearing the accumulation, but after that I completely forgot about anything work related.
The few times I've held the new born, I can't peel my eyes off of him. The little guy wins the staring contest every time. Sometimes I get a stink eye from him, when I take him from his mom's arms. But he's just too adorable to be taken seriously.
But most of my time is spent with Sempi (our first son), trying to fill the time and attention that Yoshi used to provide him. The biggest challenge so far is trying to find things to do with him. He's not a fan of leaving the house (probably inherited from me), but he insists on me playing with his trucks. After a day of playing in the house, my brain was fried from squeezing every ounce of creativity to make the playtime fun for both of us.
I used to take him to our nearby coffee shop to read books on weekends. That worked great when I did it once a week, he flat out refused when I asked him to go two days in a row.
Tiny emperor on his stroller, being chauffeured to the coffee shop.
Putting him to sleep at night hasn't been rough thanks to Yoshi. She established a nice bedtime routine. Even though reading books in bed was designed to put him to sleep, I'm the one who usually zonks out first.
Weekends are harder if I don't have anything planned. Last weekend I convinced him to go to the Children's museum where he spent a cool 6 hours playing with every exhibit to his heart's content.
Weekdays are easier since he goes to preschool in the morning. We setup playdates after school or go to a park.
He still prefers his mom over me, but I still have 3 more weeks to change that. ;)
Did I mention that we have not one but two grandmas at home to help with the baby? I haven't cooked or cleaned in 3 weeks, I can really get used to this.