I also have the Reactor 30 discharger. What I didn't like was the Fan ran continuously with the Pack hooked up. This would cause the Pack to be pulled down below 0.9v if I wasn't watching carefully (the Reactor 20 does not do this).
I re-wired my Fan to only run while the Pack was actually discharging and lengthened the leads a bit too. I like it alot better now.