My girls are 22 months apart. I certainly don't wish that they wer any closer together; especially now that YDD is older (technically I don't even belong in here anymore *sniff*) I think it's an awesome gap!
The first 4-6 months were really, really challenging but I most of that was ODD's age/stage and not really related to YDD's arrival. It would have been a brutal time regardless and I don't think I would have coped any better had I been pregnant instead of having a newborn/young baby - I was lucky that YDD is a very happy, pretty easy baby. ODD adapted immediately, there was little to no real jealousy and I swear in a matter of days she'd forgotten her baby sister hadn't always been in the house with her!
I'm a SAHM so no daycare. DH took a couple months of pat leave but couldn't start until YDD was 2 months old so I was on my own fairly early with both of them. Some days sucked, some were awesome, just like when it was only ODD
Also, personally, I found it much easier to still be in the 'baby' phase I was used to being up at night (ODD was getting molars, it was awesome
), changing diapers, working around naps. Plus, ODD was used to us being home in the afternoon for her nap so it hasn't been an issue to keep staying home for YDD. YDD gets carted all over hell's half acre every morning when we do play dates and classes and whatever and has since she was a week old, so I've always made sure to give her one good nap in her crib in the afternoon.
I'm really looking forward to this summer and beyond, as both girls are close enough in age that they'll enjoy the same sort of activities and trips. I'm already convincing DH that we need to do our first Disney trip in 2 years so we can go to a princess tea party
Also, I'd start TTC at the low end of your 'ideal' spacing because you never know. We were so blessed to get pregnant right away so we had 2 under 2 but I have friends who wanted a bit of a bigger age difference and then haven't gotten pregnant as fast as they thought and suddenly it's a much, much larger gap than they had hoped for.