I bought a house that has newer gutters and the company that installed them just cut an X for the drops. The hole is small and catches the leaves and plugs up. How are the formed drops installed? From the inside or just pop riveted to the bottom of the gutter.

 

The are pieces that can be put anywhere. Basically a 1 foot piece that has to be screwed, then tarred inside the joint so it won't leak. If you have some tin snips, you could just go and cut the X pieces out to make hole larger. That's what I'd do, then I'd go get some of the sections of leaf-guard covers they sell at home depot and cover that area. No need to use them on
every gutter. Even formed, round downspout holes get plugged up easily.

 

If the X they cut is 2x3 (the same size as a normal sized downspout is, or 3x4 as larger downspouts are) then the screws are probably what is catching the leaves. Preformed drops would actually be smaller in area than a 2x3 or 3x4 sized X, since the drops are oval.

These oval preformed drops would also need screws to attach the downspout, which could still catch leaves.

The way the preformed drop is installed depends on the installer. Some put it on the bottom and screw up from the bottom, making a terrible fortification of pointed screws around the drop. Others prefer to place the drop inside the gutter and screw down through the drop/gutter. Personally, I put the drop inside the gutter and use pop rivets to secure the drop since pop-rivets lay flatter. I seal the entire perimeter of the drop, as well as all joints and corners with Geocel brushable sealant. Usually it will create a smooth transition that will not catch junk. However it doesn't solve the problem of the screws or pop-rivets that attach the downspout to the drop. Again, pop-rivets that are the shortest possible length are best. Larger downspouts will also usually reduce clogging. Keeping the gutters clean by regular maintenance is obviously the best solution.