For those whom live in apartments

Not significantly in this case, IMO.

Dunno what the gauge of the speaker wire is with this setup, but if it is very small and you can change it, something like 18ga or 16ga would eliminate any doubt yet still be relatively thin for easier hiding.

Go with cable trunking its fast and easy to install and very affiatve at hiding wires or loudspeaker cable. Place it along the skiting board so that white plastic blends in with the white skirting or you can paint it.

Its also very, very cheap so look into it at the nearest DIY store.

Sure, it hides things, but it doesn't help to shorten the wires if they still have to run the periphery of the room.

Yes, thicker wire (smaller gauge number) would be technically better. But, if you have 18ga on hand, IMO, it's adequate for the task at hand.

Wiremold has some consumer stuff, that includes joints for the corners. Other companies have the same. Get whatever's cheapest if it looks OK.

As for cable run length, it depends on the length and the gauge. I swapped 75' of 20 gauge for 50' of 14 gauge, and it made an audible difference. I admit 75' of 20 gauge is an extreme example, but I wouldn't run 18 gauge for 50' either. That's based on our calculations here and based on other recommendations. Actually, those recommendations aren't even the most conservative. That table suggests 14 gauge, but others with more conservative assumptions would recommend at least 12 gauge for 50'.

P.S. If you get 14 gauge without excessive plastic covering, it is about the thickest wire you can easily put in the smallest Wiremold wire conduits. You can put 12 gauge in it too, but there may be lots of friction so sliding the wire around in the conduit for adjustments won't be easy.

I mention this because the smallest conduits are the most inconspicous, and they're also the cheapest.

Any difference in volume by the difference in resistance will be fully accounted for when the system levels are calibrated.

Will the FR be altered slightly? Yeah, a small bit. Audible? Highly doubtful.

Let's remember we're not talking about connecting Revel Salon2s to a pair of Levinson 33s.

Well, like I said, I had an extreme situation, where I had 75' of 20 gauge cable. There was just something wrong with the audio.

In his situation I agree though, you wouldn' hear a significant difference (post-calibration) if it were say 50' feet of 16 gauge. vs. 50' of 14 gauge.

P.S. I don't know what they were thinking when they installed that 75' of 20 gauge cable for each speaker. The guy who installed it wasn't hurting for money, and for example wouldn't think twice about spending $500 on a lawn ornament.