The CP-850 ha by far the best price / performance ratio in the 850 watt category but it only fits in 5 Antec Cases. The 1200, P182, P193 and the two upcoming cases in the Dark Fleet Series. If you don't yet have a case, there are some nice newegg combos for this PSU:
http://www.newegg.com/Product/ProductCombos.aspx?Item=N82E16817371024&SubCategory=58&SortField=0&PageSize=10&page=1
Note that the newegg lists the Mini P180 as being compatible which to this point I was not aware of and haven't confirmed.
To make the Editor's Choice List / Recommended List on this site, the PSU needs to have great electrical as well as acoustical performance
http://www.silentpcreview.com/Recommended_PSUs
For comparison purposes , the list below contains
performance ratings (10 scale) at jonnyguru.com / prices as per newegg on 02/21/2010 and ones w/ double asterisks (**) made it onto silentpcreview.com's Editor's Choice List meaning they excelled at both electronic and acoustic performance:
Antec SG-850 - 10.0 ($220) **
Antec CP-850 - 10.0 ($110) **
XFX 850W Black Edition 10.0 ($185)
Corsair HX850 850W - 10.0 ($180)
Antec TruePower Quattro (TPQ-850) - 9.5 ($150)
Corsair TX850 - 9.5 ($140)
Seasonic M12D 850W - 9.5 (NLA) **
NorthQ Giant Connector 850W - 9.5 (NFS)
Etasis ET850 - 9.5 (NLA)
Silverstone Zeus ST85ZF - 9.5 (NLA)
Enermax Revolution 85+ 850W - 9.0 ($250)
Thrmaltake Toughpower XT 850W - 8.5 ($216)
OCZ Z Series 850W - 8.5 ($200)
NorthQ Black Magic Flex 850W - 8.0 (NFS)
Coolmax CTG-850 - 8.0 (NFS)
SilverStone Decathlon DA850 - 7.5 ($230)
Enermax Galaxy DXX 850W EGX850EWL - 7.5 (NFS)
SilverStone Strider ST85F - 7.0
Silverstone Element ST85EF 850W - 6.0
NFS - Not For Sale / NLA = No Longer Available
As to the modular thing, not having extra cables is a wonderful thing but it's often over played. 100% modular does nothing for you. What's the point of having the 24 pin MoBo connector, 8 pin EPS cable modular ? Can you possible have a build that doesn't use the 24 pin. All that is accomplished by having the 24 pin cable modular is the addition of a minor amount of electrical resistance and another failure point due to it coming loose or bending pins. 100% modular is kinda like providing a Jeep with 5 spare tire mounts on the back ....I get the idea for the spare tire, but won't you be using the other 4 tires every time you drive the car ?
Most hi end PSU's today are what's called "hybrid modular" whereby the necessary cables are hardwired and the optional cables. To garner that lately important 80 plus certifications, manufacturers are paying more attention to the teeny bit of resistance that the connector adds.
http://www.tomshardware.com/news/power-supplies-psu,8016.html
Enermax, Seasonic, and Corsair all told us that if you're looking to maximize efficiency, go for a non-modular PSU.
Hybrid modular gives you the best of both worlds, hard wiring the necessary cables and leaving the "optional" cables modular.