Is there an alternative to rasterize ?

I use a lot of what I called Stabilized Power Pin for doing that kind of repair. I'll corner pin track a feature on a plane in Mocha, then set up a surface that gives me a frame around the thing I want to replace or repair. I usually add an image or one of the grids in Mocha so that I can verify that the track is perfect. 

Back in After Effects, I duplicate the source footage layer, rename it something like Repair 1, then apply Corner Pin to the duplicate. The next step is to turn off the Corner Pin effect on the Repair 1 layer and add CC Power Pin. The four corners in CC Power Pin are tied to the corresponding corners in the Corner Pin effect using a simple pickwhip expression and then Unstretched is turned on. This gives me a new layer that contains a stabilized copy of the area that I tracked and pushes in on the image so have a lot more pixels to work from. The Repair 1 layer is pre-composed moving all attributes to the new comp and then Corner Pin from Mocha is applied to the Repair 1 Comp in the main timeline.

Did you follow that? Now that I have a comp with an enlarged and stabilized version of just the area I want to fix I change the original footage duplicate layer with Stabilized Power Pin recipe applied to a guide layer and start working on the repairs. Sometimes I just insert an image, sometimes I use a shape layer, sometimes I use a copy of the stabilized corner pin layer as a source for the clone tool. I add lens blur to mimic Bokeh or focus, noise, grain, and any other color correction needed in the stabilized and enlarged nested comp (Repair 1 Comp). Because the original footage is now a guide layer I get a repair in the main comp that only is changing the pixels I need to change. It's a very efficient workflow. Mocha Pro comes with an option that performs basically the same thing with one click, but the animation Preset makes it very easy to do with Mocha AE. 

The great thing about this technique is that you get enlarged pixels to work with and modify, then the repair is reduced to the original size making it almost impossible to tell that you are not looking at a normal shot.

Here's an old tutorial that I did showing the workflow from previous versions of After Effects:

I'll have updated versions of this tutorial available soon in a new tutorial series I am working on.

Follow this link for a copy of the Stabilized Corner Pin animation preset for you to try. 

There are also ways to use Mocha AE to motion stabilize a shot, speed up rotoscope work and masking, and do a bunch of other great things when you need to add something or remove something from a video. Let me know if you have any other questions. 

Screenshots? Render settings? I'm pretty sure you are making a mess somewhere. of course you're right - just inverting the tracking data should not degrade the footage, so something must be going on. I'd also check the clone tool settings. The paint tools are pretty buggy in the last few releases. perhaps some bad setting there is making a mess of things.

Mylenium

If your shots get blurry, you are messing up sub-pixel positioning. Really nothing more to say than that. There is no need to use CR in such a scenario. Either you're really shifting positions or you introduce additional motion blur and such, so start by verifying that your motion track keyframes don't get quantized and you're not accidentally moving stuff around while working.

Mylenium