I came across a Fiddleback Forge Bushfinger that is done in Commando Style (No Liners). Are there any benefits or drawbacks to a Commando Style?
I have flip-flopped on Andy and Phil so much that I'm sure it made their heads spin. When I first discovered Fiddlebacks, I was strictly into EDC / kitchen type use and hounded the heck out of them to make more knives with thin blades, and also liked thinner handles. But then when you go to doing push cuts and the thin blade digs into your thumb, it's time to grab a thicker bladed knife. That's why you just need to buy 100+ Fiddlebacks. lol
But seriously, it depends on your intended use and preferences. When it comes to the handles, commando usually interprets to a thinner handle, but not always. Andy could have decided to make a fat-assed broomstick type handle without liners and stripes.

You really need to get a top/spine view of the knife you want to buy to know how thick it is and what type of contour it has. If it has liners and stripes, you could have either a really fat handle or a really thin handle. It just depends.
A thicker handle is going to give more purchase and comfort for heavy use. A thicker blade is going to give a better landing spot for your thumb and do nicer feather sticks, but will split an apple vs slice it. A thinner blade will typically slice food nicer but not be optimal for bushcrafty things. A thinner handle also will conceal better under a shirt.
Oh, and then there is the steel stock taper and I'm sure there are whole threads on that topic. A full tapered tang will obviously give a heavier knife overall and might come in handy for chopping. A tapered tang would equate to a bit less weight and would change the balance point of the knife.
Hope that helps.