I'll begin by saying that large macaws are really not good "starter parrots".

When thinking about what it's like to live with one, I can name a lot of adjectives: 

Dominating.  Oh, my, yes.  These birds push you.  They are wired to dominate and they are very, very smart.  A macaw who thinks he/she is "in charge" is challenging to live with at best.  You really can't afford to allow them to become the "alpha parrot" that they are capable of being.  The word here is "loving domination".  The bird has to trust you, but also has to be constantly reminded that you are in charge, not him/her.  This isn't easy to do.  You have to be firm but loving, no matter how irritated you are (and believe me... some of the power struggles are very irritating).  And you have to be consistent.  "No" always has to mean "No".  

Affectionate.    I have never seen any companion animal as affectionate as our large macaws are.  Although they sometimes are feeling too caffeinated to be snuggly, they love to be cuddled, petted, and sweet-talked.  Want to melt the heart of a member of the ARA genus?  Just sing them a little love song, something soft and soothing.  Or offer a scritch under the chin or a little head rub.  You haven't lived until you've heard a macaw purr.  

Demanding.  The best way to explain this is by example.  Our Laka likes to go to bed on her own schedule.  Generally this means going to bed earlier than we'd really like her to.  In winter, she wants bedtime to be about 5:30 and in the summer, well, 7 pm is about as late as she is willing to stay up.  After that she wants bedtime - and RIGHT NOW!  Failure to tuck her into her bed cage once she's decided "it's time" earns us some ear-splitting screaming. 

Expensive.    Aside from the funds required to acquire the bird and a big cage, there are a lot of other expenses.  This includes food (half of which will not be eaten, but tossed around the room... more about that later), vet visits, and toys.  Toys are probably the biggest expense.  Toys, if they bird likes them, are likely to be destroyed after a while.  Very little holds up to that huge beak.  And, of course, some toys (the wooden ones in particular) are intended to be destroyed.  Plus, the bird needs a variety of toys so that you can rotate them in and out of the cage.  They need lots of variety because they are so smart.  

Intelligent. Smart?  Did I say smart?  I've read and heard that large macaws have the reasoning capacity of a 4-year old and the emotional intelligence of a 2-year old.  What that translates into is a bird who can remember things quite well, can unlatch it's own cage, is capable of playing tricks on you, and so on.  It also means that mental stimulation must be provided.  Bored macaws sometimes self-mutilate and develop other behavior problems (chronic screaming, aggression).  Keeping them entertained is quite a job.  That means toys - lots of them - and lots of parrot/human interaction.

Messy.   About half of what we feed our macaws ends up on the floor.  Sometimes that's the floor of the cage... sometimes that's the floor under and around the cage.  I am constantly amazed that Laka is so good at throwing cooked black beans out of her cage in a way that they bounce and then roll underneath her cage (where they are harder to find and clean up).  Laka can easily hurl food a distance of 3 feet - with so many things she eats being round, that means that pellets and other food roll around and end up all over our lounge room.  And if that isn't enough - sometime around her first birthday, Ned and Kelly (our green-cheeked conures) taught her a fun new trick: shooting poo out the side of the cage.  Fortunately the seed wings on the bottom of her cage catch most of that, but not all of it.  I live to vacuum and scrub.

Loud.  This bird's volume can actually damage your hearing.  Fortunately, macaws don't scream for joy (as cockatoos do) and they don't scream for long periods of time.  But when they do, oh....  I like to say that Laka's voice can peel the paint off the wall and shatter concrete.  At full blast she is about as loud as a smoke detector (actually, I think she's louder than our smoke detectors).  And sometimes the vocalizations upset the neighbors (and not just because they are loud).  Laka makes a squeeling noise that sounds like a child screaming.  She's also started yelling "oh, oh, oh" in a way that sounds like a woman moaning in pain (I have no idea where she got the idea for this one).  I'm just waiting for the day the police show up at my door to investigate possible abuse...

Mischievous.   Macaws are "busy".  They aren't inclined to be happy just sitting on a perch and being pretty.  No... they are "busy"... constantly exploring and getting into everything they can.  Whatever you are doing, they are happy to "help".  Forget being able to leave them unattended - that is, unless you don't mind having everything in that room chewed and shredded.  It's amazing how many  inappropriate things a macaw can find to chew - my walls and baseboards, curtains,  windowsills, wooden chairs, coffee table top and legs, piano, bookshelves and the books on them, kitchen cupboard doors - anything Laka can reach is in danger.  You name it, she's chewed it (or started to).  All companion birds need a good deal of "out of the cage" time each day.  Our conures and eclectus can be let out and allowed to fly around without worrying about anything more than, maybe, some poo having to be cleaned up.  But the macaw?  Her we have to watch constantly, just as you would a human toddler.