well an sd slot is handy for storing roms, pictures and videos and for other stuff if your 16 gb internal is full or if you dont have money for the 32gb one but on the g2 you could also use otg sdcard readers.
Sindroid well not everybody transfers stuff via wifi and app. I transfer the most with cable to my pc since i dont have micro sdcard anymore and i guess fmradio is also nothing for you cause that also consumes hardware space. Sdcards dont need to be slow depends on the class you buy.
Dont get this comment negatively sin cause i dont know how to type it different :/