I pre-ordered Sun after the announcement of the new Ultra Beasts, but before the legendaries were announced.
I liked the Ultra Sun exclusive Ultra Beast better, wanted something a bit different after playing Moon, and to be honest, wanted the daylight hours in the game to match real life haha.
I was a bit worried when they announced the legendaries. I have all legendaries in my living dex, but quite a few of them have been through trading on the GTS - and I am not sure of the legitimacy of one or two of them (some of them seem a bit too perfect). It is my goal to eventually catch everyone legendary myself.
While I would have loved Lugia and Kyogre in Ultra Sun, seeing as I have multiple versions of Ho-Oh and Groudon, I will eventually be able to catch those in HeartGold, which I am currently playing.
The only legendary that I won't be able to catch myself in any of the games I own, or have lined up to play in the future, is Xerneas (I played Y, and don't want to buy X just for one Pokemon). So I was stoked to see that it is going to be available in Ultra Sun.
I am once again happy with my decision :)