We can burn DVD's in three qualities i.e. DVD HQ(High Quality), DVD SP(Standard Quality) and DVD LP(Low Quality).
i) DVD HQ : Has resolution of 720 X 480 in NTSC TV format and 720 X 576 in PAL TV format and video bitrate of 8000K. This option lets you burn 60 min. of high quality video content onto the 4.7 GB DVD.
ii) SP (Standard Play) : Has resolution of 352 X 480 in NTSC TV format and 352 X 576 in PAL TV format and video bitrate of 3400K. This option lets you burn 120 min. of video content onto the 4.7 GB DVD.
iii) LP (Long Play) : Has resolution of 352 X 240 in NTSC TV format and 352 X 288 in PAL TV format and video bitrate of 1750K. This option lets you burn 180 min. of video content onto the 4.7 GB DVD.
Power2Go always burn the DVD in HQ quality and do not provide any option to change it. So, it always burn 60 min of video. It has nothing to do with speed.
Other burning software of CyberLink provide you option to change the HQ, SP and LP.