It's not so much the energy regen. Although that is a concern, it is mostly that they
WAY increased the cost of Chaos Volley which is so stupid since you can't do any good damage with it w/out casting it a few times in a row and by the time you do that you have no mana left to cast it any more. Also the Endurance cost now on energy rift is ridiculus, It was 15 end and now it is 45 end. To me a adjustment would be to make it like 20 - 25 end. Not to make the spell basically useless since the most end you can have is 100, and the end regen is way nerfed atm, it takes 4 full seconds to tic
I was still waiting for them to fix the end cost of Shocking Grasp which they nerfed bad in Beta. A end of 40 gives it only 2 casts and that it, and the spell doesn't even do that much dmg. So basically it is a totally useless spell and is never used (well it was somewhat usable from the lvl you get it til about tlvl 10 when soloing).