Oh no DJ! I never had any problems with my Fitbit One. It performed well. I went through two of them as I accidentally sent one through the wash and the other flicked off my pants at the shops when I was struggling with something and resting it on my hip. That led me to a wrist one thinking it might be better for me. I bought a Fitbit Flex and as far as tracking steps go it's great. Pushing a trolley or pram still gives me steps (although they say maybe not as many due to burning less calories without the arm swing but I've done the same route with and without the pram and have had very similar results). I've recently had some issues with my device but Fitbit are replacing it. The new one is in the post now.
I do miss being able to see my steps on the device (Flex just has five dots to give you an indicator). But I can see them on my phone so it's not too bad.
I have really noticed the difference in my activity levels without the tracker. Can't wait to get it back and focus on the challenge again!