Novak made the 4 cell version w/ NO heatsink or fan because that was what some 1/12th scale and OVAL guys asked for.
OVAL guys have been using these w/ 2s LIPO for quite some time w/ no issues...
It would depend on your application, and the temperatures you'll be running.
The basics of the ESC are the same , being 4 cell though, there is NO LIPO CUT OFF setting, so you have to make sure you KNOW how much you are running your lipo packs (especially if bashing vs. racing) or if you run longer than normal length races.
(The POPULAR oval class = 21.5/LIPO and in a 4 minute race you only use approx 1500 mAh of a 3200 battery) so a cutoff wasn't needed.
R/C Racing since 1985 ~ Santa Maria, CA (Central Coast)
2001-2012 - South-West Tour R/C Oval Series - R.I.P.
...will the SWT be revived? Time will tell, but we ARE returning to the VELODROME in 2016