No, of corse not! ...ok, just kidding, but i love BoA items. Not just Hierlooms, but all BoA items (25th Aneversery Bliz Bear, Cold weather flying book, etc.).
Recently i started a Rogue alt to mainly level in PvP BG's. But i quickly found out that i should level at least the first 5-6 levels of a bracket doing PvE. Being 20 in a 20-29 WSG/AB is no fun. I have almost all of the Heirloom items i can on him (shoulders,chest, weapon, bow, trinketx2) and it really makes the leveling experience more enjoyable. At first i wanted bliz to come out with more Heirlooms because there are still plenty of slots to fill up. But then i thought about it... If i have Heirlooms in every slot then gear is no longer a motivation to do anything. You are covered from 1-80 and will never need to replace your gear till endgame.
I'm still on the fence on whether that would be ok or not and figured I'd bring it up here and find out what you guys think.
With Heirloom gear i am actually more excited to gain the next level. When you have Static gear getting to the next level is irrelevant unless you are getting a new talent/skill/spell. Your stats/dmg don't really change because only your base stats change. With Heirloom gear every time you level the gear changes as well. I find myself getting excited to see what the stats change to the next level. It's hard to explain, it's kind of like being excited to see what your Poke'mon evolves into, lol... can't believe i just said that... oh how i miss those days.
Although you wont NEED any gear from Instances you will still at lest want to do them 1-3 times for quests. I actually find myself doing them anytime I get a group for nostalgic reasons and to break up the monotony of the solo grind.
Quest rewards will seem useless (unless your a disenchanter lol). I use to be motivated to do long/hard quest chains because they yielded better items. It would make you feel more involved when you were invested in the reward. But i guess with heirlooms you are now free to just quest where you want to, and not feel restricted by "I need to make sure i quest here to do this chain to get X gear." You can just go try new areas that you've never leveled in before and not worry about optimizing your questing.
...ok, after typing this out I've realized that having a Heirloom in every slot would actually be great! More short term motivation, quicker leveling, care free zone selection, no fighting over gear drops, etc. But maybe there's something i'm not seeing. Please post with your opinions, i'll add a pole for a quick response.