Recumbents are not faster up hill but they are not noticeably slower either. The difference in weight is usually less than 5 pounds between a recumbent and a comparably equipped diamond frame bike. Other than the extra weight, they are just as fast up hills. They are faster in the flats, downhill and in the wind because they have 1/3 less cross sectional area.

As far as visibility, they come in all sorts of flavors. People who ride the low ones usually just put a flag on them to help with visibility. There are high recumbents with great visibility. I am making one myself. It is a "High Roller" recumbent on 700c wheels that will look like this: