union bindings

they are made with pretty much the best plastics in the world from dupont.. thats what they specialize in.  they also use a lot of other unique materials and processes.  they are the only company to make their own hardware out of grade 8 aluminum instead of grade 4, they use extruded anodized aluminum heelcups... its only compromised once, rather than being bent and pressed 3, 4, or even 5 times, so its strong.  they use magnesium ratchets which are twice as light and 4 times as strong as aluminum, so on and so forth.  i personally love them.

the sierra contacts are going to ride pretty much like contacts, which are a slightly less responsive binding but theyre not super soft or anything.  if you dont prefer something on the more responsive side then they should be fine.

if you want something a little more responsive, more like a general mid-flex bindings, try forces.  i have owned a lot of forces, as well as burton cartels/triads, and those three are all very similar in response.  if you like how triads feel, i would go with forces.

SLs used to be about the same as forces, just lighter and more technical, but the newer ones are actually significantly stiffer.  they rate forces at 7/10 and SLs at 9/10 now.  if you want something stiffer than your triads (i assume thats what youve ridden, since you asked how they compare), then sure, SLs.. but if not, forces are your best bet.

Just wondering why you don't recommend the contacts is there a specific reason or just that the forces are better??? The contacts come in at a fairly reasonable price and are comparable to some of the top bindings?