How are you planning to use them and how often are you checking that is a big part of what trap to use also what kind of budget are you on and do you have a lot of trap theft. I have trapped for over 55 years and used everything from longs springs, Sterlings, MBs, Victors coils, jump traps, Montgomerys or Montanas as they are now made and called and as of late Bridger dogless. If I am behind locked gates or on private Sterlings are a Cadillac but heavy and a bit harder to set. I have not tried K9 but they look like a good trap but heavy and pricey and I would not want to loose them or pack them far. Montgomery and Montanas are in my opinion a great trap, affordable to use, loose and replace and hold well. Longsprings are cheap buying them used and do a great job especially with PIT pans. I run a two to three day check running 2 foot of chain with 3 swivels and a 18 inch stake on prairie and tilled ground and loose very few coyotes with any of my traps save my Sterlings all my traps are 2 coiled and like I said very few pullouts.