The cable management is excellent but the sheer size of the case means that some cables can come up a little short. Had no problems with PCIe cables but have used more SATA cables than I would have liked with two power supplies now which is not a big deal. Just meant more clutter to cable tie behind the mobo.
Can't really fault the case. More an issue with PSU manufactures skimping on cable. Latest PSU, a Corsair HX1000W, has done well though. 6x SATA drives, sound card requiring floppy power (Xonar DX), and numerous molex powered fans only needed 3 modular cables in the end with a bit of planning / measuring before installation. If you have a modular supply you can always buy longer cables. Most manufactures recommend you use only their cables (or course) but provided you don't buy cheap crap I can't see any problem.
I've recently done a couple of builds for friends / family and used OCZ modular supplies, and had an OCZ non-modular myself until recently. All came with long cables, especially the PCIe. Length not the only issue. The spacing of the connectors can also be an important factor and again OCZ do well here.
