The problem is that if you walk less than 10 steps and stop, those steps are lost. Over the course of a day, it makes a big difference for some people. My fianc? has a fitbit, and it'll show 1000 steps before she walks out of the door in the morning. That is an accumulation of steps from the closet to the sink to the wardrobe back to the sink, etc. My band will show 300 steps even though I am doing essentially the same thing. At work, I am up and down pulling files, going back to the desk, getting coffee, etc. These trips are short, 10 steps or so. But if I sit back down quickly, those steps appear to be lost.
The downside to the fitbit is that some activities give you a false step. My fianc? is a two finger typer, and she will get a bunch of steps from typing! While I get mad when at the end of the day I only have 8,000 steps and my fianc?e has 15,000, part of it may be that she walks more than me, but I think that I probably walked more steps. While I don't want undercounting, I don't want over counting either. (As a touch typer, I don't think I would get the typing boost....my wrist stays still!)
Mine works ok lawn mowing, but I do have an electric mower. it does still vibrate and does not affect my count... what may cause a problem is that your hand is not swinging when you walk.
The band is very accurate if you are out for a walk. If you are trying to actually count your actual steps, it may not be the most accurate.