what's good about it? ARE YOU SERIOUS? O_o"
If you have one, you won't need to worry about changing the brushes as much as the brush motors. There is no need to tune it. Besides, it saves so much power, so you will have more time to run it. They are quiet, and blah blah blah...
for running 6cell 23T, my preference is VFS1 since I can adjust the freq/punch to get more power out of the system. for running mod, especially those low T motor, I like GTX more (eg, I run 4cell with 6x1 motor, 5cell with 7x1 motor).
Hope this help.