To chip in my 50 cents:
For me, I do use it as a replacement or better set, as a next step for pokemon on level 60 or more.
Since the Levels are the highest on that floor, I only train on the first floor (where the entrance is)
There are two "areas" the water and the Land.
Water is easier to judge, it has Psyduck, Goldduck and Slowpoke as common, and Slowbro as uncommon encounters.
Bhimoso wrote this in his guide:
So the takeaway for me is:
Pokemon with Graß and Electric moves can be trained pretty easily in water, Pokemon with Dark and Bug moves have to potentialy flee from the Ducks.
Defensewise if your pokemon resists (or is imune to) Water and/or Psychic Attacks, the cave is also a great place to train.
You should be aware, that Slowpoke and Slowbro are tanky, so expect them to potentialy tank a few attaks before. It you're pokemon is weak against Psychic consider fleeing from the Slowpokes until you can oneshot them.
On Land you'll encounter more pokemon, the common ones are Arbok, Electrode, Goldbat, Graveler, Machoke, Parasect, Primeape, Sandslash and Venomoth. You'll also enconter Ditto, Licktiung, Raichu, Rhyhorn and Rhrydon as uncommon pokemons. I'll skip the Rare ones.
Most of these Pokes are the usual cave pokemon, so the same Rules apply: Water, Gras, Psychic, Electro, Fighting and Ground are effective to a good part of these, other types are harder to train since you'll have to flee more often. Also be aware, that Graveler as one of the most common pokemon often has Sturdy and will hit you with Stone Edge, Double Edge, Earthquake or Explosien which can give you some trouble. Also for training with Immunities, the Arboks, only know Poison-Attacks, so Steel-Types can be easily trained against it.
My verdict for land is, that you have stronger Cave-Pokemon which makes it a better version of Victory Road to train BUT it has more clutter, which may drag it's eficency down. It your Pokemon is high level enough or has enough other typed attacks, that disadvantage will schrink.
TLDR:
Yes, for 80% it can replace Victory Road, but look out for more bad Matches who'll reduce efficency and may make it the worse choice.