I have used both of these kits and had outstanding results.
I blew out one of my fins jumping on my directional and the fin and the fin plug came out. I was able to affect a repair and its as strong as if it never happened.
Kitefix is ridiculously effective. I just crashed a kite, tore the canopy fabric and punctured the leading edge. The repairs took about an hour from start to finish, about $5 in materials, and the kite is ready to use in 24 hours.