I've had couple razer products. What I figured is that their newer stuff is quite bad compared to the "old school" razer producs. Example: My friend bought the krakens and they broke after the 1st month, so he changed them for a new pair and they lasted for another 2 months.
I wouldnt recommend the watches but thats just my 2 cents.
I don't think it's worth it, personally. There are plenty of better looking watches that also track your fitness without paying a premium for the brand. Razer tend to overprice their products.