[imported_Gang-Bang]

Extra mana would suck to be honest, it's like +stats. If you meant extra mana regain about +10% like we were talking, yeah it's not harmful I think, it would be useful for gank/PvE, and if you can't use shield with it to get regain noone will use it on tours. The thing is againest decent pvper on duel stones/tour you work the whole duel to make him run outta mana, if he could just wear some armor+shield and get his mana regained in no time it would seriously ruin pvp. But if as soon as you equip shield regain stops working or if you can use it with shield but can't use it on duel stones/tours it will definitely be useful for gank or hunting... For example I to be honest liked ganking on no-vus much more cos there you didn't run outta mana and you could fight againest bigger groups with just one partner. Here two guys have almost no chance again five decent pvpers, cos even if they won't die instantly they will just keep running and healing, and waste their mana very fast, so they can't dump back...
Oh and btw, if it will be implemented and it just won't work with shield make sure smart guys won't make macros like equip/unequip shield... Like you know, the guy hits you with bard, you quickly unequip shield and equip it again in 2seconds

Edit: Also very important thing that this armor shouldn't be expensive, so people actually use it. Not like hell hally or black widow or cho ko nu, which is very good for gank but it's so expensive that noone will ever risk weapon which worths 50-100k