On balance, I'd say it isn't worth it.
I stopped at one child for this very reason. I'm not a natural mother and I never realised how much of an introvert I was. I hate noise, arguing, defiance and being responsible for someone else's needs all the time.
I regularly congratulate myself for at least having the sense to stop at one. I've made some bad decisions in my life, but not that one.
I try so hard to be a good mum and I have a lovely bond with my son, but there does seem to be an element of fakery in it all.
Now that he's started school, things are better but 0-5 nearly finished me off.
My husband and I were together for 12yrs before we had our son. I kept putting it off because I really wasn't sure I wanted any. However, finally fell into the trap of thinking 'but what if I regret it' so I had one.....
My son is also a real fire cracker type personality. That in itself poses a huge challenge (he does also have wonderful traits!). I have friends with very laid back, compliant children and I often think, I would have enjoyed parenthood far more if I'd had that type of personality.
I would say for anyone on the fence about having kids, if you decide to go for it, then just stop at one!