iMacsoft MP4 Converter is a commercial video converter. It can be used to convert video files of different formats into files encoded using H.264, MPEG-4, DiVX, and MPEG-2. This converter can probably open any video file that you have on your computer. If you click on the "Supported formats" drop-down menu when you are loading a file, you will see all the supported formats. I opened both an MKV and an AVI file without problems.
Once you have loaded the files that you want to convert, you can select what format you want to convert them to by selecting it from the drop-down menu on the left part of the screen. You can convert different files to different formats. In other words, you don't have to convert all the files in your conversion queue to the same format, like you have to in other converters.
In terms of performance, I think this converter and other converters by iMacsoft work pretty well. They are fast and the files that they convert look very good.
The developers released two versions of this app. There is a PowerPC and an Intel version.
In short, if you are looking for a converter that can help you convert your files so that you can play them on mobile phones, Apple devices and the like, iMacsoft MP4 Converter can do the job quite well. However, if you are looking for video editing features or GPU acceleration, you have to look for another application.