I will reply tonight when I get home on the specifics as I can't get to the email account from here. I will also post a picture. I had Chad build one that drops down an inch or so into the kettle.
There was movement in the spider, but I would not say it was as rapid as the rolling boil I have in the open kettle. I added both pellet (Magnum for bittering) and flower (Saaz) to the spider, though I ended up with a lot of flower in the kettle (not really worried about flowers clogging). I do use a bazooka screen and a screen on my funnels to catch the hot break. There was not much hot break at all that made it to my funnel screen...maybe covering <10% of the screen. With pellet hops and no spider, that screen would clog 5 or more times during the carboy fill, requiring me to stop, wash, sanitize, and repeat. It is important to note that I recirculate with my plate chiller, and I put the hose into the spider which may have caught the majority of the hot break during recirculation as a bonus...
Saturday I filled two 6.5 gallon carboys without any interruption in process. Like a dream come true! Not to mention prior to completely clogging, this slowed down the drain process. Not so this time, which subtracted another couple of minutes off the process.