I built a CFC a few years ago, and it wasn't that difficult. That being said, @Brett Mullin recommended going 30 foot long, rather than the more typical 25 feet. Glad I did, and again, thanks Brett.
It works great, and isn't difficult to clean. I don't know about the physics of the interior of the plate chiller, but I personally don't know how good the flow through the corners of the plate is, and therefore how clean they get. Also I believe the inner space between plates is smaller (that's why its more efficient), but also allows for more chance to become clogged (especially if you suck any kettle trub up). I think the advantage of plate vs CFC is efficiency and smaller size, but my CFC chills down the wort to mid 60's as fast as I can pump it through with my chugger pump in cooler months, and I barely have to slow it down in the heat of summer to get it below 70°F.
Yes cleaning is more difficult w a CFC vs Immersion Chiller. I usually will make acouple gallons of One Step or PBW in a spare brew kettle and recirculate during the boil, then recirculate rinse water, then hook up to my boil kettle and run boiling wort through it the last 10 min or so of the boil to sanitize.
As to water usage, u know its more efficient than a IC, but I usually run the runoff into my pool. When it's too cold to brew outside, I bring my subpump in and fill my 10g igloo Mash tun with ice water and recirculate. That works wonders. I'd say it takes about 2x the volume of water to chill vs volume of wort, but that will vary depending on the size of your CFC/Plate/IC too.
