Well..I'll be honest. Our oldest was 36m and the middle was 18m when the baby was born. It has been really, really hard. On the other hand, it has been really, really fun.
The hard parts - feeding people and getting out of the house. I've had supply issues with all 3, so imagine trying to nurse, pump, supplement, take all kinds of nursing meds, deal with thrush, etc, all while feeding and cleaning up after a 3yo and 1yo...So those first 6 months were a blur. A happy blur, though, because lots of people helped us. Someone came (an older lady from our church) and held people, rocked people, read to people, changed people, fed me, etc for TWO months, JUST because I learned to ask for help. Brittone2 even met her. I found that preparing dinner with 3 almost under 3 was nearly impossible, so I learned how to do once-a-month-cooking after people fed us for nearly 3 months. A mothers helper came one night a week when DH was not going to be home for dinner and bedtime. We got a housecleaner every other week. A neighbor came 2x/week to watch the boys while I took DD to preschool. (BEST thing ever!!! - She has no idea how much that meant to me. Unless she's reading-lurking here! hope so!) So, it wasn't that I got excessively lazy, but my hands were just really, really full! I think I counted 6-7 people (grandma included) that helped us get through a week at one point. Yikes.
Getting out of the house to run errands is one of the hardest things for me. Knowing I need to go get a prescription, but have to take a double stroller AND wear someone to get in there just sux. I've tried to let someone walk, and we just all end up in a messy heap. Maybe one day it will work. I dream of having 4 daylight hours by myself to run errands/do returns/etc.
I think SO much of it depends on your personality under stress, and the personalities of your DC, and ultimately the space between your DC. I tend to be fairly chill usually, but my shoulders have been "tight" for most of the past year. We've made it through the first year, so hopefully, it will get easier once DS2 is walking...or will that make it harder?...hmm...
The fun has been unreal, though. I just have to stop and laugh A LOT. Like the other day, we had this triage situation..1) baby has a cold and is wheezing, so I nebulize him 2) DS1 has recently started PTing and poop rolled out of his unders onto the floor where he was playing in the LR and 3) DD moved a stokke chair in the kitchen to get herself some scissors (?!!!) and started cutting something in the kitchen. What do you do? Who do you tend to first? We've destroyed restaurant tables, traveled to see family, gone to waterparks, amusement parks, Disney for a night, and all kinds of stuff. We've taken thousands of pictures but I can't find uninterrupted time to make baby books or any family photobooks. I think that's the hardest for me...not being ABLE to do all the things I would want to do for each DC the WAY I would ideally want to do them.
Yours sound like they have space between them. Space can be a good thing. But close together can be fun too, eventually, I've heard!