Ok, to start this off - I work at a knife shop. I sell all sorts of knives to people and I sharpen\fix them all day long. Awesome decision to go with Benchmade. They are easily one of the most practical and affordable blades on the market, plus the warranty is beyond excellent. I'll try to keep this to the point. For a work knife, the Contego is definitely one of the best knives you could buy.
Use - can be used with or without gloves on, which is great. Also the carbide glass breaker is awesome as a "just in case" tool for EDC
Blade Shape - The reverse tanto is WAY better than a drop point for work. It has the piercing power of a regular tanto, but still has a belly to it (the curved part of the edge) for slicing and regular use. Tips on knives are only good for one thing, piercing things. If you constantly use the tip, you will over pierce everything you're trying to open and damage what's inside. The main reason I love this style, is along with it being one of the strongest blade styles out there, it also acts like a sheepsfoot blade. Which means that if you have to cut a strap, ziptie, rope, or etc... off a package, you can slip the knife under it then turn and cut with plenty or working room between the tip and the package below. Drop point knives don't allow for this.
Blade Steel - M4 is the sexiest stuff around. It's tempered to 64 Rockwell, making it harder than D2 - yet it cuts better than S30v or many other knives. This is due to it's high carbide content (research this topic for further knowledge). Also, it's high hardness makes it highly wear resistant, as well as resistant to edge rolling (which is the main enemy of knives that cut things like plastic ties and rubber often). Believe me, I've seen these knives come in after cutting through fences in Afghanistan and they're still fairly sharp; no joke. As far as corrosion, don't worry about it. First off, it's coated in 3 micron of ceramic Cerakote. This stuff is durable. After 3 tours of war zones by a guy in Blackwater PMC his knife is missing maybe 5% of it's coating. So yeah... it's tough stuff. However even if it does rust, this stuff isn't the same as the crap at Big 5. It doesn't pit and flake like other steels because it's way denser. It literally gets what we call a "patina" on it, meaning a layer of brown coloring that comes off with light polish; but if left alone stays the same and doesn't get worse unless it's super abused (ie left in a tackle box after taking a dip in the ocean for 3 years).
Sharpening - I tell customers every day, and it drives me nuts when they don't listen. Every knife owner should own crock sticks!!!! Seriously! No oil or water required, just come home, run them down each stick 3x, grab a beer and go inside to watch tv. That's seriously all it takes. If you want to be lazy, then use them once a week and start with the coarse rods, 4-6 strokes on each side then move to the fine rods. Either way, it takes either a few seconds or less than 10min to do. CPM M4 has the amazing properties of being insanely hard and wear resistant, while still being easy to sharpen. Trust me, I sharpen these on crock sticks for customers that I haven't seen in two weeks or more - and who abuse the hell out of their poor Contegos all day long at work; yet it takes me 10min or less and I have them back to razor sharp (no joke). It's due to the chemical make up of the steel, which again, isn't something to go into here, but believe me when I say I speak the truth. The steel is the heart of the knife, and this heart beats like a lion.
Downside - The only downside to the knife for some people can be it's size. This is a great EDC, but if people are wary of it where you live, keep in mind you're buying it for work. Carrying a box cutter in public can be frowned upon too lol. It can seem large, but when compared to other knives like the full size Benchmade Barrage, the blade is only 1\4" to 1\2" larger. Where the size comes from is the handle. The reason for this is because it was designed to be used as a kubaton as well. For me, this is a definite plus. Also, when cutting aggressive things like thick synthetic cable rope or ties, the larger blade excels at that. One final word of advice: DO NOT buy the serrated model!!! Are you buying a knife, or a mini hand saw? 80% of your cutting power is in the lower 20% of the blade. Trust me, you've never had a steel that will cut like this. You don't need the serrates. Every customer I've had that has bought the serrated model against my advice has regretted it.
Anyways, that's my input on it, and I sell them to MANY happy people every day. I own many knives, and many that cost more than this one; but if you threatened to take them all away but one, I'd have to keep my Contego. I could go into all the reasons why this knife is better than the other models you mentioned, but I'm pretty sure it's strengths speak for themselves. If you came into my shop and told me "I need a good strong work knife" my first question would be "Are you willing to spend money on a good knife, or do you want a crappy budget BIG 5 knife?" and if you say 'no thanks to big 5' then I say "This is the Contego..." and we have this conversation.
EDIT: While this knife can cut other steel\metal, just don't do it. Other metals, like baling wire, have been hardened. Keep in mind that even crappy steel can damage good steel because it has been hardened completely. Even fully hardened scrap can damage wonderful tempered steel. That's what $5 case hardened wire cutters are for.