Well I cant comment on having two kids yet because my #2 is still to be born BUT I thought Id give you a choosing to have them close together view.

We did it for health reasons, we have fertility issues and pregnancy does not go well for me so I wanted to get it over and done with ASAP. We had originally planned to have them 3yrs apart to avoid 2 in nappies etc. There will be just under 16mths between my two boys. Some days I get scared at the idea of trying to coordinate a small toddler and a newborn; and others I am excited because I'll be that little bit closer to freedom once they're both toilet trained and in preschool within 1/1.5yrs of each other.
My son is a very easy going, flexible toddler who has more good days than bad and even his bad days arent super difficult so that helps alot knowing he will probably assimilate to becoming a family of 4 very easily. He has also not yet hit the physical period of wanting to hit/poke/shove anything or anyone, nor will he be very jealous because he wont remember there ever being a time when it was just him and babies are fascinating to him atm.

The main issues with having two so close together is the pregnancy is more draining physically and emotionally because the first 1-2yrs of bubs life is full on. Ive struggled being pregnant with a 6-15mth old who doesnt understand that Mama cant be a climbing frame and that she's tired because she's growing a baby. Ive also had health issues with the pregnancy which has included hospital trips and bedrest so that was tough. Im lucky that I have good friends who stepped in to play Mum while I was gone and DH has picked up the slack a bit. Another thing is I am VERY lucky my son has been walking since 10mths old and now sleeps in a big boy bed. I couldnt imagine still having to pick him up and carry him around at 30+wks pregnant OR lift him and put him in the cot everytime he wants to sleep.

There's also the feeling of guilt that youve taken away some personal time with the older child because you've had a pregnancy to experience during a time when baby #1 is learning new things and wanting all your attention. I feel like Ive taken something away from my son, not being able to do all the fun things toddlers want to do esp when they first start walking. I know he wont care and its really not THAT big a deal but I still feel guilty every day. Its like he really only had 6mths of just him and me because even though bub isnt technically here until a few more weeks Ive been pregnant for more time than he's been alive and been slowly getting him used to not having my attention 24/7.

So I say maybe wait a few more months and then start TTC (provided you dont have any issues with fertility etc) so that you atleast have a mobile, semi-independent toddler to make things a tiny bit easier.

Good luck!