Best setting for super that i research from the internet and i tried out myself is

Container, MP4 -> H.264/AVC
Audio -> AAC LC
Resolution -> 320:240 (choose your resolution based on the original video aspect ratio but dont exceed 320)
Aspecct ratio -> Let SUPER set the ratio automatically which depends on the resolution. (e.g. 4:3 for a 320:240)
Video Bitrate -> 384kbps (this is sufficient and any higher bitrate wouldn't give any significant difference in quality)
Audio Bitrate -> Any will do but i've found 128 kbps to be suitable.

Please check the "High Quality" box on the right and leave out "Top Quality" and the rest (will make the filesize very big)
Do click on the H.264 profile and make sure these settings are set to,

h.264 profile =Baseline(CABAC off)
H.264 levels =1.2

(these settings are important and u can refer to this wiki link to learn more)

Hope this helps.