Solution-processable metal-halide perovskites recently opened a new route towards low-cost manufacture of photovoltaic cells. Converting sunlight into electrical energy depends on several factors among which a broad absorption across the solar spectrum and attractive charge transport properties are of primary importance. Hybrid perovskites meet such prerequisites but, despite foremost experimental research efforts, their understanding remains scanty. In addition, the toxicity of lead may restrict market clearance. Here we show that in these materials, the appropriate absorption and transport properties are afforded by the multi-bandgap and multi- valley nature of their band structure. We also investigate the nature of the photoexcited species and evidence exciton screening by collective orientational motion of the organic cations at room temperature. We introduce related dressed quasiparticules to discuss carrier mobility. Chlorine doping hinders such collective motions, leading to improved light-harvesting and transport. We further suggest CH3NH3SnI3-xBrx as a good alternative to circumvent toxicity.