Need advice about Fitbit type thing

I love love love my fitbit. I have the one that tracks sleep but they have others that don't and are cheaper. So far I love mine. My next purchase will be the polar ft4 because I'm interested in what I actullay burn at Zumba, I'm sure it's not as much as the one site says, but if I know how much lower it is it may motivate me to work harder.

STRIIV is great for challenges and rewards. You can get the self contained STRIIV smart pedometer or the free STRIIV app which can use the phone as the pedometer ( not ver accurate) or link with the STRIIV Play device.

Look also,at Bodymedia Fit- probably the most accurate and gives the most information.

I've been using the Fitbit to great effect. Started out with a Fitbit Ultra and have since gone to a Fitbit One. Not sure which one I like better but I do like that the One will sync up through my Galaxy Note 2.
I think that, as with most things, you get out what you put in, using the Fitbit is great for tracking walking, running, etc and that is what I have been doing for the most part.

You've already ruled out a HRM so I guess the options are a FitBit or a GPS watch. It depends on what you want it to track. A GPS watch will not work well indoors if you are interested in say, your steps during a day of work. If you're looking at an outdoor walk/run then a GPS will give you the most accurate distance. I have the following:

FitBit Ultra - I use it to keep track of TDEE and also how much walking/activity I get in during a typical work day (I work in a gym and often have spontaneous "mini workout sessions" throughout the day so I find it helpful). I wear my FitBit 24/7 except when I am in the shower and find it motivates me to move more, including chores around the house that I would not ordinarily be motivated to due (such as laundry)

Polar FT7 HRM: I use this during my formal workouts, such as gym time and cardio for an accurate reading of heart rate and calories burned based on my personal info.

GPS watch: I use this to track my distance outside and keep a steady pace. It also has a HRM feature if I choose to use it but when running outside I have found my Fitbit calories to be within 10 calories of my HRM so I don't bother to wear the chest strap with it anymore and just go from the Fitbit for calories and the watch for distance/pace.

I hope this is helpful but which gadget you get all depends on what your goals are. I have all three simply because my goals have evolved over time. I started with the HRM for workouts, then got curious about TDEE, then increased my running to a point worth tracking.... hence gadget central.