Have the hertz energy 3 ways up front and hertz energy co-ax in the rears. Running off a JL 300/4 at 75 watts for the past year. Last week blew a woofer, on hertz website found the set was rated at 100 but the actual woofer was only rated at 70. Sound wise really enjoy them but it took me alot of tuning for about a week. The tweeters can sound sharp/harsh out of the box without tweaking. I replaced the woofer on both fronts with Polk MM6501 woofers from a component set. The Polk woofers are at 2ohm though but are "over sized 6.75" (but hard to tell the difference looking at them) and rated at 100 watts according to the back of the speaker. Personally the Polk woofers really put out the mid bass up front much better than the hertz energy woofers did and I'm pretty impressed so far. Will see how long they last, next round will spend more money and go with something better up front, personally I don't know if I would do hertz audio again, maybe the high energy line. I would would have to compare what else I could buy for the money vs the Hi-Energy hertz line. Don't know how the Polk MM 6501 components sound but have read good reviews for the money, I know the woofers from the MM6501's sound great!
Side note local dealer said Hertz would not send him replacement drivers on the energy set but would on the Hi Energy.