Japan could still join on Ententes side, meaning another Russo-Japanese War. They would disregard Russia, having beaten them in 1905. Fatal mistake.
Main German problem in West would not necessarily solved with CP Russia. There only as much troops as they can send before Ardennes tranportation (roads, rail...) gets bottled up, slowing down the offensive. No victory before Christmas, sorry. They would however slowly slug toward Paris, eventually capturing it.
Main difference will be Russian grain feeding Germany. No starvation.
This means CP is much stronger in prolonged conflict.
And since Russia is fighting away from its core territory (Far East, Persia, Kaukasus, Central Asia), they won't lose so many men they have to recruit too many peasants away from their fields (since their limit is transportation capacity, not lack of manpower), and this means no 1917 starvation-caused revolution.
German fleet does not need to fight in Baltic, meaning its easier to starve UK.
Russian trans-Siberian railroad is completed, so its relatively easy to fight Japan.
Alliance of Three Emperors wins in prolonged conflict.