Here's Cliff on the subject throughout the years...
Sorry for lack of paragraphs.
The whole cable thing is really BS. The only audible and measurable difference is solely due to the difference in capacitance. The cable manufacturers trying to convince people of skin effect, strand jumping, etc. etc. is just hooey. All you need is well-made cable. Low-capacitance is preferable but if treble rolloff really bothers you that much then put a buffer in your guitar. I like Whirlwind and ProCo myself. Well-made, durable, and low handling noise. And priced reasonably. / Anyone looking for "high-end" cables: go buy some good old Belden or Alpha, etc. cable and some Neutrik or GL, etc. connectors and save yourself a few hundred dollars. / Actually, it is quite common for speed of transmission to be dependent upon frequency. This is a phenomenon known as dispersion. It happens because the path length is a function of frequency (due to skin effect, etc.). That aside, the amount of dispersion in a 20 ft. length of cable is practically impossible to measure, let alone hear. Dispersion is only significant when transmitting wideband signals over many kilometers of cable. Happens more with optical and acoustic signals than electrical. Monster cable and many other cable manufacturers rely on dubious science and patently false marketing claims. The only real, quantifiable, and audible effect a cable has on your tone is due to the capacitance of the cable and the quality of the shielding. The capacitance rolls off the high frequencies and the shielding, well, shields the signal from noise. The difference in the capacitance and shielding factor between your run-of-the-mill Belden cable and Esoteric Audio Labs Quantum Infinium Super Ballistic Low-Loss Megablaster III cable is negligible. The price, however, is not. You can build your own cables that will perform as well, or better, than anything Monster or any other "boutique" cable maker can build for a fraction of the price. Simply buy a spool of good-quality cable and some good Neutrik or G&H or Switchcraft connectors and spend a little time with the soldering iron. If you don't want to do that, there are plenty of "no-name" cables that perform very well and have a reasonable cost. Parts Express sells some very good, inexpensive cables. Remember, it's basically just a piece of coax. There's only so much you can do, and anyone who tries to sell you 20 ft of wire for $100 is a snake-oil salesman, plain and simple. Here's a basic test: if they have a cable that is "directional" then they're snake-oil salesman. // 1/2011: The only audible difference is capacitance. Don't believe any of the nonsense about directionality, "micro-distortions", skin depth, etc. If you truly want the lowest capacitance possible then use a short cable into a buffer. The reason capacitance is audible is that it forms a low-pass filter with your guitar electronics. The more capacitance, the lower the cutoff frequency. Pretty simple. Personally I look for durability over all else and use 10 footers. Cable manufacturers would like you to think there's more going on. There isn't. And please, for the love of Peter Griffin, don't get suckered into buying special power cords.
Cliff, HRI: In general I think high-end cable is snake-oil but I will concede that you may get less high-frequency loss by using expensive instrument cable. Power cables OTOH, are nothing but hype. Do you think the outlet is some magical, perfect AC source? There's at least 100 ft. of crappy, solid, unshielded Romex between the outlet and the distribution transformer. A few feet of "linear, oxygen-free, strand aligned, blah, blah" isn't going to make any difference. Any decent, heavy gauge power cable will work just fine and save you quite a bit of money.
Cliff, HRI: The primary intent of balanced cabling is to improve EMI immunity. Balanced cabling combats both conducted EMI and differing ground potentials (commonly referred to as ground loops). A full treatise on the reasons would be more than I could write here but suffice it to say for cabling within a rack balanced cabling is rarely needed. It really is intended for long cable runs. I'd hook it all up with unbalanced cables to start and if you have any problems seek to isolate the problems. The G-Force balanced outputs can be used with plain old unbalanced (instrument) cables.
Cliff, HC: Another sure sign of a snake-oil salesman is when someone can't point to any hard evidence: double-blind test results, laboratory measurements, etc. but instead refers to "reviews" and "customer testimonials". Instead of measured parameters you get vague, obfuscating terms like "pinch definition" and "soundstage". Or my favorite: "organic". It's a great tactic too since anyone who claims they can't hear a difference is easily dismissed as not having a discerning ear. There's a whole fascinating psychology behind this and it gets exploited every day in many different products: rare-earth metals that cure joint pain, potions that reverse hair-loss, etc. etc. This same BS goes on in the audiophile world and unfortunately it's now being foisted on the guitar community. Don't get me wrong. Cables can and DO sound different. But there's no secret sauce, no magic elixir. It's just basic science and you can achieve the same results at much lower cost. I'm also not saying that these boutiique cables are bad. I'm sure they're very well built and probably have decent electrical properties. If you have the disposable income then by all means buy them. If you're like me and cringe at the idead of spending absurd amounts of money for some wire and connectors then, well, you get the idea.
