If you have a modern, high-end machine that you use for your production work, local processing may well be your best option, especially if you don’t plan to run other tasks at the same time as processing files.
If you have a high speed symmetric internet connection, cloud processing may well be faster unless you have a very powerful machine. When processing via the cloud the limiting factor is often the upload speed of the files from your machine, so if you have a strong internet connection for uploading files you might benefit from cloud processing.
For moderate internet speeds, a bit of trial and error might be needed to see which processing option is faster based on the specs of your machine.
In cases where your internet is slow, we strongly suggest local processing.