I did the same thing. It works great for HERMs and cleaning is easy. I intended to use it for chilling also, but the stir motor created too much foaming/aeration during the first part of the cooling. If you aren't doing some kind of stirring or recirculating during chill it will take a long time and since the lid is now in the way, you can't stir. I ended up going with a counterflow chiller.
I still use the recirc coil during mash. One thing I would change is the coil spacing. Make the coils concentrated at the bottom. If you have them spaced out like I do, you need to fill the keggle all the way up which takes longer to heat up and change temp.