If you are really keen on a big zoom beyond the 100-120mm equiv range, then you will struggle to find a compact that also has a better sensor and sharpness. Bear in mind that sharpness has a lot to do with lens, and if you have a superzoom, to get the superzoom, the manufacturer is usually forced to give up on lens sharpness. The only way around that is for them to make the lens massive beyond belief. Personally, I'd question if you need a superzoom...many people think that being able to zoom in and out a long way is a good thing, but most of the time a short range of zoom or a fixed focal length is more than enough. If you are occasionally shooting, say wildlife, then you could be ok with a high-end compact that gets out to around 120mm. Chances are as well that if the camera can take a fisheye conversion lens, then there are also telephoto (eg 1.5x or 2x) conversion lenses too that you can pop on for such occasions. Such converters always lose you some image quality but a good one will be barely noticeable, and for most of your shots you'll appreciate the better lens and camera anyway.
Just my thoughts.
A potential good candidate for the above scenario could be the Olympus XZ-2. Excellent lens and image quality, responsive, etc. Also, there are fisheye lenses available around 0.25x conversion (so that would make it a 28mm*.25=7mm fisheye, nothing to sneeze at!), and Olympus probably makes the best quality tele conversion lenses out there for their compacts. With the B-300 on you end up with a good quality 190mm f2.5, which would cost an arm and a leg to get on a DSLR. Corners a little soft but that doesn't matter when you are using it for that purpose.