The contrast between Charles and Andrew as Naval Officers was noticeable and much remarked upon.
Charles went by the name Arthur Windsor, and was keen to be judged on how good (or otherwise) he was, and not on the fact that Mummy owned the firm. Very dedicated and with a lovely dry sense of humour. Could be a bit of a stuffed shirt at times; thoughtful rather than instinctive. Earnest is a good way of describing him. He was respected by those that knew him.
By contrast, Andrew always made sure everyone knew that his first name was "Prince". The tale goes about (I've no idea how true or otherwise it is, but it rings true - as do all the best urban legends) that when he joined his first ship, he introduced himself to the Captain with words to the effect: "I'm Prince Andrew, but you can call me Andrew." To which the inevitable reply (according to the story) was: "I'm your commanding officer. You can call me Sir." There was a reason he clocked up so many hours on anti-submarine detection during the unpleasantness Down South was that this got him away from the matelots, who universally loathed him.
Charles wanted to know what made the people working for him tick. Andrew couldn't care less about such lesser mortals. I always got the impression he regarded other people as "not real, just things that exist to further his well-being."
I hasten to add that this is my personal view, based on observations and the gossip that did the rounds. Other views may well be held by other people.
Any substance to the rumours that Andrew is not Phil the Greek's? I always thought he looked very different from the other 3.
I think Diana is very much a poster girl for "be careful what you wish for" - from what I'm led to believe, she set out from a young age to harpoon Charles. Only the reality did not meet expectation.