Matumbo 2 vs. Zoom Vic Elite/ Zoom Vic 2

Matumbos or Mambas, take your pick. Matumbos are a tad comfier than mambas, IMO. you are correct, IMO, vic's a too lightweight, cushion wise, to be running a 5K in...unless you happen to weigh about 105lbs.

After running track for far too long now I've found that running a 5k in victories is certainly doable, but your calves pay the price the following week. I personally prefer matumbos over most all other spikes. They are slightly more lightweight and the reduced plate allows them to be easier on your body. I use matumbos for all but the fastest of track workouts and most all 5k/10k races. Best of luck with the new races!

I'd definitely go with the Matumbos for the longer stuff. I can really feel it if I don't, and the Matumbos feel more fluid for the long haul.

Partial to these:

http://amzn.to/1Tv6PHe

mostly because they aren't trying too hard but still look solid.