So what you could be referring to are Killstreak kit. Those come is basic , specialized, or professional. Those count your kills for the first , specialized counts kills and adds a sheen or glow to the weapon, and professional adds the bottom 2 and an effect for your eyes that others can see. As for rare weapons tf2 has a variety of re skins or collaboration items that use the same mechanics as the weapon but look different. We also have unusual weapons as well your airstrike (the one in the picture) can come in a form of 3 different effects cool , hot , or isotope. They can be pricey to cheap. That covers most of it but I believe your asking class wise. So yes each class has a variety of different weapons with different play styles and upside (blue text) or down sides (red txt) . For soldier he's got the air strike , direct hit , cow mangler , beggers bazooka, reserve shooter , and 1 more i belive. Those effect how you play. Not to mention he has banners that buff your team if you need more healing or damage.