The last version built by Chainfire is v2.78, available in the XDA thread.
Anyway, using Phh's Superuser seems a better idea:
• Open source (unlike the last version of Chainfire's SuperSU)
• Magisk (also open source) is mainly supporting Phh's superuser.
• You will need the next root solutions to bypass the new Android (security) features
• We more and more have to hide root to have working features/apps. Chanfire's suhide is also closed source.
• You have notifications from Google Play to update SuperSU app.
• It just works! Use the "full unroot" option from SuperSU app, reboot and flash Phh's superuser to try yourself. (don't forget the nandroid backup of course )
Are you sure v2.78 is the last one by him? He says it himself here that 'v2.78 is indeed released today by CCMT. I have not built it myself yet. ' - http://forum.xda-developers.com/showpost.php?p=68474748&postcount=11415 That post is from 1 sep this year and I'm sure I got the Play Store update to v2.78 a lot earlier ... maybe a few months back and I did install it. I just read that the latest stable release actually maintained by Chainfire is 2.76