Never try to compare a Parrotlet with a Conure. The closest you can get to a Conure in a smaller form is a Lovebird, and even then there are HUGE differences. Since you have a Lovebird, I'll use them as an example.
Lovebirds are feisty, playful, and clingy they are essentially a miniature angry Conure. I know that sounds rather funny, but Lovebirds tend to act like a Conure on a bad day. Unless they are truly properly acclimated (which is scarce) they tend to be slightly mean. Now if you found a breeder who properly acclimates you'd never have that issue, and you'd find they can be just as sweet and loving as a Conure. You can hold my chicks on their backs for heaven sakes. However, Lovebirds have a low talking ability and females can become aggressive single person birds if they are not constantly socialized.
Conures on the other hand are mischievous! They are always testing things, pushing your buttons, trying to get in trouble. They are like a child in many ways. I've noticed that even when hand-raised, your going to expect a bit of the terrible twos. I love my Conure, he always keeps me on my toes. However, for a lot of people they are too much. Some people become very frustrated when their bird decides to test them. I've seen Conures who one day decide they don't want to step up, and would like to nip instead. With a Conure you don't wait and say "I'll try tomorrow", you work with it right then or it's something they've learned they can do. But the best part about Conures is 20 minutes later they're kissing and cuddling.
Parrotlets remind me of Budgies when compared to the two. If you stick your hand in a non-tame Lovebird cage, your likely to get a nice bite. If you stick your hand in a Parrotlet cage it's likely the bird will fly off. They are much more flight than fight, they are mellow and docile birds. They can be fun for some people, but I personally like a good challenge! A bird that keeps me on my toes and gets in a little bit of trouble.
I think it's very important to go with species. Go interact with some different birds at a friends, breeders, or even a parrot store! Most of the time they have similar traits.