I have a goldendoodle. Regarding temperament, you can either get the poodle type of high energy dog or the golden type of laid back dog. You can also get soft wavy hair or tight curly wool! My girl Lexi (a bit under 7 years old) is definitely a golden inside though she looks very much like a poodle outside. She's very mellow and generally just follows us around inside. She has very curly hair that really is wooly, not loose curls. We have her trimmed in a poodle "puppy cut" which is just an all over trim with her golden retriever tail and ears left silky and longer. We have her trimmed every 6 weeks, and she needs a bath at the inbetween spot (3 weeks) generally. You can learn to do it yourself or you can have it done (like we do), but you can't ignore their fur or you get a mess!
We decided on a doodle because we wanted a golden but just couldn't take the hair (we had "babysat" a friend's golden numerous times). Like any big dog, you really need to get them into obedience training as a puppy and keep them well socialized. Lexi went to puppy classes and then a few sessions of obedience. A big poorly trained dog is a disaster no matter what the breed! Make sure you know the breeder and make sure you know how they socialize their puppies. Ours was family raised and mom and the entire litter lived in the house with children and cats, so Lexi never had a problem with either.
BTW: Don't believe the hype that cross breed dogs don't get the genetic issues that single breeds do. Lexi has a pretty bad case of hyothyroidism that is definitely genetic and associated with golden retrievers. Treating it is simple - a pill morning and evening.
Pam