Just got mine and installed, very easy install, the only thing they should probably warn is that after turning off the water and flushing the toilet there is still some water in the tank. While I knew that some may not. 
Any rate have used it a few times now and pleasantly surprised at how effective it is.  While the water pressure is decent at my house, not great, I can’t imagine turning this thing on anywhere close to full strength, very powerful stream!