Dear Jess, you know there probably isn't all that much difference in styles and model variations. The cheapest certified types generally work as well as the most fancy and expensive. That said, there are differences for reasons and everyone has a preference.
Bent gates are marginally easier to clip on the rope end of a draw, as the bend sort of gets the loop of rope you are clipping right "in" the gate. They also usually give you a slightly wider clearance than the equivalent straight gate, so you can hook fatter ropes/ chains etc.
Wire-gates are lighter, somewhat stronger (tensile strength wise), and far less prone (coz of the lighter gate weight) to "gate flutter". This is the vibrational "flutter" gates do when you fall on a draw. No, it really does happen, though only rarely does this lead to a rope unclipping - but it can and has. Also wiregates do not freeze-up or block with ice and snow as easily as bent/straight gates; hence they are esp. popular for ice/alpine climbing.
Dogbones:The slings between crabs (biners). Trad climbers usually prefer to just use slings, as they can be extended to keep rope drag at a minimum (important with nat pro like cams and nuts). But sport climbing draws can be varied too. Stiff draws like the Petzl Express (with lots of sewing between the ends) can help you reach a draw up to a just reachable bolt, but this feature can also cause the draw to "ride-up" the bolt crab and open it's gate (this happened to me once). Floppy dogbones are more common, and usually do a great job. The might be just a semi-flat loop of webbing (el cheapo) or have two distinct retainer bights at the ends to clip crabs into. These are a definite improvement in keeping your biners correctly orientated. If you fall on a biner (crab) that is not being held in the correct way by the dogbone (sling) it can cross-load which severely weakens the crab! It may well fail. Recently many draws have got little rubber things at one end or both to stop a biner from twisting at all in the dogbone. Some climbers just twist on a rubber band or bit of climbing tape to achieve the same thing on el-cheapo dogbones. If it is only at one end, then that is the rope catching end! A free-er bolt end biner to dogbone set-up allows some movement to keep rope drag/ cam-walk (nat pro) and such down.
Personally I DO think the snag free "key-lock design on any biner (straight, bent or wire (rare)) is worth it. I hate struggling to get snagged biners off a harness, hanger, sling or whatever. Key-locks don't get this problem as much. But until about 5 years ago the patents for them were held by one company. Now many manufacturers are making variations of this.
quem deus perdere vult, primus dementat