I've seriously been considering returning the Ultra and getting the Plus. I have adjusted to the size and weight of this beast. The main reason I was considering returning the Ultra was because of the camera focus issues. The camera has received two updates since I got the phone and they have definitely helped. I know that the focusing still isn't as reliable or as fast as my old S10+ and there is definitely a learning curve to understand its limitations.
I am probably going to keep the Ultra though because what attracted me to it is the quality of zoomed in pictures that it can take in the right conditions. The zoom camera has a relatively "slow lens" (in photography terms!) at f-stop 3.5 which means it needs a good amount of light to take good pictures (ex. outdoors in the daytime or well lit indoors). But it definitely can take very good long zoom pictures and video.
When there is enough light, I have taken some really great shots that I know I wouldn't have been as good with the digital zoom on ANY previous camera phone that I have had. I've shot pictures and video zoomed out to 10X with some really great results. Even beyond 10X, the picture quality is passable for most social sharing.
I think I can make it work in most of my shooting situations which is usually outdoors in the daytime. The way I look at it is that this camera can take good pictures at longer zoom levels (up to 10X to even 30X) than any other camera phone I have ever had given the right conditions. Heck my point and shoot pocketable dedicated cameras only has up to a 4X zoom!