That is actually what I am afraid of...my issue comes into play that I am assembling my CP now and I am in a hurry to finish (firstly, because I want to play with it, secondly because we host a lot of holiday gatherings soon 2 Thanksgiving dinners, 1 Birthday party, 1 Baby shower).
I won't be free to buy a 4 way for a bit though, so it will have to go in after the CP is built. I also don't own a router, I borrowed one to do what I needed to do. But really the biggest issue is that I designed a really complicated CP so in the end I was hoping to be able to just plug something underneath so I won't have to take it all apart again. I suppose I can buy one, try it bottom mounted and if I hate it, do the full dis-assembly to put it on top.
If no one else chimes in here later that is probably what I will do, I'll also update this thread on the results for anyone else who goes looking in the future.