Coupla things. Nickel Silver is a notoriously bad conductor. It has lots of resistance and is used in some instances for heating elements because of its high resistance. Brass is a much better conductor and way back when, when I started in HO scale (like in 1963???) my old brass track ran just fine without a lot of constant cleaning. However NS looks better, solders just as easy and (I really don't know if this is just hype but we've all heard it) the oxidation is conductive. Supposedly, we should be cleaning our track a LOT less if we used NS rails and not brass rails. However, that's a moot point since I am not aware of any brass N-scale track out there, so we're stuck with either NS or stainless steel if you count Arnold/Hornby track.
I have never constructed a layout for myself using code 80 track. I've used ME code 70, with code 55 sidings and industrial areas, but those old Ntrak modules are long gone, and my layout/module construction has used code 55 and code 40 rails for over 20 years.
On some of my very early wiring using 55 and 40 rails, I soldered all my joiners and assumed that current would be sufficient to run my engines, but using phone wire (Probably 30AWG) on the module ends (soldering to PCB ties at the modules' ends) proved to be bad practice with everybody's trains noticeably slowing when going through those sections.
I also had a LOT of problems with broken rail joiners (all soldered) especially on the hand laid code 40 tracks which represented light and medium duty trackage with ties further apart than the ME code 55 mainlines. I suppose this caused more flex on the rail joiners when cleaning with a Bright Boy even when mounted on cork roadbed, which then caused oxidation at the soldered joints and eventual failure. I tried just butting the code 40 rails together on a PCB tie and soldering them all together, but that didn't work well either.
Plus, the modules/sections were wired by at least four different individuals and although they worked okay in DC, whenever there was a problem, it was a Chinese puzzle crossed with a Gordian knot all made into a big rat's nest and took an inordinate amount of time to solve problems.
When I finally decided to go with DCC five or six years ago, I was determined to rip out ALL of my old wiring and toss it in the trash, other than my DC Tortoise leads, which is what I did.
I did a lot of study about it, and since my layout will fill a 40' X 40' space when complete and have a couple of hundred feet of mainline running, I thought I'd wire it very closely to Ntrak's DCC wiring standards since they are always running BIG layouts.
I've never liked terminal strips because of the time factor and they're just another non-soldered screwed joint to loosen up or corrode over the years so I used as few of them as possible, and instead used what I term "Sub-buses" to connect my short rail feeders to, which then get attached to my main power buses.
I decided to use Ntrak's recommended 12AWG wire for the main power bus wires and on further recommendation, I found high purity, low-oxygen, fine stranded 12AWG speaker wire in a Black/Red Zip configuration for a helluva deal on eBay. Had to buy 600 feet of it however, but I'll have to buy more before I complete my layout.
The sub-buses are also lo-ox, high purity 14AWG stranded wire, which my solid core 22AWG rail feeder get directly attached to.
Since I can run the sub-buses directly under the mainlines, my 6" feeder length is long enough for me to put an "S" curve into each feeder as added insurance against pulling off one of them during transportation.
I mark which power district the feeder are attached to up above by sticking a short piece of vinyl electricians tape near the feeders in the appropriate colors.
Contrary to another opinion on this thread, I LOVE genuine 3M Scotch Lock IDC Suitcase connectors, and after a bit of research, I now know why they are used extensively in the automotive industry...they don't corrode (the metal "displacement" blade is a special alloy that discourages oxidation), they're quick, they're reliable (if the correct size and style are used), they're removable, and they instantly insulate each joint...and they're cheap if you shop rather than buying them from Micro Mark or Radio Shack or Lowe's or The Home Depot.
Here's a photo of my new high-speed/low-drag DCC wiring in an upskirt shot of one of my Echo Yard sections, illustrating the above points graphically:
I also run a 12VDC 14AWG speaker wire bus to power the Tortoises and my Digitrax UP-5 plug-in/Loconet panels.
To alleviate any problems I've had in the past due to oxidized soldered railjoiners or broken butt joints over PCB ties, I elected to put a feeder on EVERY STEENKING PIECE OF RAIL, which so far (in five years) has worked out GREAT for me and my son. I wish I'd done it decades ago as we simply do not have electrical problems any more making a section of rail dead.
So, as to 22AWG feeders working okay if they're longer than 6"...yup, that's probably true up to a point, but as my rule of thumb goes, mine always are no longer than 6" because of my sub-bus protocol which they all get attached to instead of a centrally located terminal block, which I've eliminated.
My philosophy is "Make your wires thick enough so that you KNOW you're not going to have problems" rather than push the limits. Just use bigger wire than you really need, or fine wire in shorter lengths than will cause problems rather than pushing the limits. So far, this philosophy has worked really well.
As to whether to use stranded wire for feeders or not, my choice of solid wire is because it solders up quicker for me using my resistance solderer and offers way fewer nooks and crannies to encourage corrosion in the hostile environment of model railroad rails.
