of cos the 2nd one is better. see how linear the response is till 20kHz. the first one has a big spike at 5kHz. even if u install at 90 degrees angle it still can't play linear up to 20kHz.

not sure wats the bottom one indicates. i juz look at the freq response at diff angle. u see 0, 90 and 180, those are the angle pointed at u, at 0 degress it's called on axis means directly pointing at u. off axis means pointing away from u. i dunno why the first one on axis is 180 degress, usually it's 0 degree. to know if it's on axis, juz see the graph with the furthest extension and highest peak, those are usually on axis cos u dun lose freq due to angle problem. altho some tweets are more suitable for off axis installation. juz refer to this type of graph to know wat it is capable of.