I am getting my first wide angle lens and need some advice. Most of what I shoot is landscape photography, however, my only lenses are the Sigma 50 1.4 A, and the Canon 70-200 2.8. I am about to purchase a new wide angel lens and I want to go with a prime, Sigma Lens. When I saw the announcement for the 14mm prime I was set on getting that, but one of my more experienced friends suggested a 14 would be too wide for me (Having no wide angel experience). He suggested I go with the Sigma 20mm instead. Can anyone with wide angle experience give me some more advice? I'm an experienced photographer going on paid assignments. Will a 14mm have too much of a learning curve? Would you suggest the 14 or 20, given my situation? Thanks!