Hello Ben F
You make a very good and often not though of point. EASE OF ACCESSIBILITY to your model subway track and stations, tunnels, for track cleaning and repairs, maintenance, etc. As far as track, both (all types) have their pros and cons. As far as Atlas and Gargraves....
ATLAS Track is either solid Nickel Silver rail or Brass Nickel Plated Rail -- and will NOT RUST
Gargraves is steel (hollow tube) rail and WILL RUST
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ATLAS Track is designed for showing more and realistic detail on the roadbed ( tie plates, tie spike heads)
Gargraves Track has no details nor tie plates or spike heads
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ATLAS track will not work well or if at all with LIONEL locomotives with MAGNE-TRACTION -- because of its NON-STEEL rail composition
Gargraves steel track (like LIONEL and other steel tubular and hollow rail track) WILL WORK VERY WELL with MAGNE TRACTION locos.
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Both track types look great in full ballasted roadbed environment
People I know who use both Atlas 2 or 3 rail track, Gargraves Track and Lionel and other Tubular type and "tinplate" type track -- still have to clean their rails periodically of gunk and crud --- and at times clean the wheels of some of their cars (mainly lighted passenger cars) to prevent lights flickering. My (deceased a few years now) pal and neighbor John B had that problem using both steel Lionel tubular and some straight Gargraves track -- and used his LIONEL fluid based track cleaning car to help. I rebuilt his LIONEL based 3-rail layout for him back in 1998-99.
RUBBER TRACTION TIRES installed on many 3-rail O gauge locomotives contribute to the black gunk and crud deposits coating rail-heads. We don't have nor need traction tires on Trains, locomotives, traction cars operated 2 rail scale track.
Even with CAREFUL lubing, oiling, of wheel axle's and journals, some little oil works it way to the wheel treads and onto the rail heads ---attracting dust, grit and etc. to form that sludgy crud thin film on rail heads. No problem on real railroads -- their railcar brake shoes grind-scrub the wheel treads clean and the sheer weight of the prototype trains keeps the rail heads clean on actively run-upon track. !
On my O Scale NYC EL system using Atlas 2 rail track -- I clean and keep my rail heads clean regularly --- which keeps the wheel treads on my cars clean. I use a rag with a bit of hair clipper (Oster or WAHL Brand) oil (which also promotes electrical conductivity) to rub the rail with a rag to remove that black thin film slime that accumulates. Funny, you don't SEE it on the rail heads --- but it comes up black on the cleaning wipe rag ! My rails gleam in the light on my EL -- thats the way I like them !!
MY HO Mainline Passenger trains Railroad around the train room (shelf) layout uses mixture of steel rail track, brass and nickel silver snap and flex tracks -- and these rails all have to be scrapped (Brite-boy scribbed) or rag & solvent wiped clean every few weeks or so after regular operation periods - to take care of crud and oxidation.
My under-EL Trolley layout trolley track is a bit more of an experience for cleaning. Its in a sort of tunnel effect of sorts with tall building along both side of the EL above it. I use 2 gondola cars filled up with loads dead AA and AAA batteries - making two VERY VERY HEAVY gondola cars -- towed behind a 2 powered trucks diesel loco-- and I run this consist with a few freight cars on the tail -- around and around on the trolley layout under the EL to weight-scrub the rail heads clean --it works.
Imagine trying to manually wipe-clean trolleys tracks under the EL -- see video below and the two photos
https://youtu.be/BJKH3niTIDs
Regards - Joe F