Yes, it works fine without Start11 if you search the forums you'll see that a lot of people have this problem, the advice generally given is uninstall, purge, and reinstall, but as I said, that is only a temporary fix. I'm not sure if it's related to the size of the files, or the number of files, in my case I transfer large numbers of large files (Video editor, so lots and lots of multi GB files moved from location to location, betwen local, network, and external drives)
I have not seen ' a lot' of such reports but I am not saying it's not a concern.
The only thing that comes to mind is that for such transfers, Windows Explore (which Start11 has hooks into) becomes unresponsive. When this happens, and you check task manager, is that the case, that WinExp shows 'unresponsive'?
Stardock Product Lifecycle Manager