I agree. My phone always shows way more steps than my fitbit. For instance, when I was in Disney/Universal this year, on one slow day, my fitbit showed 20,000 steps. My phone (Samsung health) which was in my hip and in a locker for some rides, showed over 30,000 steps. I have never had a problem with too many steps with my fitbit. In fact, I have always found it a bit stingy.
I have several fitbits going back to when they first became popular. Needless to say, I think they are very worth it. However, I would not purchase the Charge (either HR or regular.) The back of it that holds the charger breaks off very easily. Fitbit will replace the charger during the first year, but as soon as your warranty is up, they say forget it. And they won't provide a replacement part. They will only offer you a 25% discount to go spend another $120 on a new one. So, you are spending $150 on a device that will most likely be useless in a year. If you want to check out the problem, there are numerous threads about it on Fitbit's site.
That said, I LOVE the new Charge 2. (I used my discount on it after I used up my replacements on my Charge HR.) It has a different charging that won't break and I love the features on it. Totally worth the money for me.