I've tried both SabNZB and HellaNZB, installed with this howto. Both have problems at my setup:
- SabNZB crashes when the webinterface is used. Downloading works, however without a webinterface it is inconvenient

- HellaNZB stalls after a while, mostly after working for some quarters of an hour. Only restarting helps. The log file doesn't offer useful info. On internet it shows that stalling of Hellanz happens more on different platforms (especially earlier versions).
Currently I am using this "work-around" (quite drastic, I must say). In cron.hourly I've put an executable script with this contents:
killall python2.5
sleep 10
/opt/bin/startHellaNZB

If others experience these problems too, a warning in the howto is advisable.

I am using:RT-N16-1.9.2.7-rtn-r1799.trx of the 15th of July by the way. I haven't tried newer versions of OLEG firmware