I use to breed them for many yrs. IMHO, they are not for the inexperienced. Think of an amazon in a tiny body. One of the most painful bites I ever got was from a parrotlet.
They do make great companions but you must buy a handfed baby or rehome one that is handtame. Most parrotlets left to sit in bird cages in stores and hoes revert to aggressive, wild behavior. Just because they are small does not mean small cage. They are extremely active birds. They can learn to talk and have cute little voices. Here in the states the most popular is the Pacific Parrotlet. They have been bred in many color mutations.