Tried 2 games as entente and got my a** kicked two times.
First time I had no problem taking belgium and sacrificed my fleet to stop english convoys to france but had made no advance in Serbia before I got streamrolled by Russia, second time was the other way around, managed to almost take Serbia when I got streamrolled I did try to garnison city in germany but it didn't work (Konigsberg is the only one that held).
When the game starts it says that Russia needs time to mobilize, looks like it doesn't *grins* it has like 10 times the amount of troops I have. But that's not really the problem imho, the problem is the way russian troops can easily use infrastructure and go by train to berlin in a few turns. Even by putting garnison in every city the Russian troops move too fast and can just gang on each city one by one. I'd like to see some movement penalty for russian troops (or have their troops start very far from the front without any trains at disposal) which would ensure a slower entrance in war.
Also it seems Russian troops are better than germans (they usually can move and destroy my troops in the same turn with just 2-3 of their units even if I'm entranched for a couple of turns)
Of course it's only first two play run but I'm not a "blitzkrieg" player so I would definitely like a few more turns before having to face Russia
I too have some concerns about how well the Russians perform. One problem is that it's damned difficult to design a game where history can replicate itself, when so much of what actually happened was determined by "soft" factors like leadership, personality, psychology, and chance. I do agree that the Russians seem to move too fast and too flexibly, with too few restrictions, but I cannot quantify that, nor can I specifically give a suggested fix, as I'm not 100% sure there is a problem. I could just be terrible as the Germans. On the one hand, it would seem logical to make the Russians less mobile and less durable; give them good starting power but make replacements and upgrades more expensive, and perhaps cut their movement by a fraction. The problem then though would be you might make them totally incapable of posing a threat to Germany, and the Germans were very concerned about the Russians--indeed, for a while in 1914 the Russians moved pretty expeditiously into East Prussia.
At the scale of this game, it's hard to balance these things. The way things are now is pretty good. I think maybe a few tweaks to rail movement and the ability of the Russians (or anyone else) to move rapidly with infantry forces deep into enemy territory might help. In France it doesn't matter much, as the distances are so short. In the East, it does matter, but you still need to have the possibility of grand routs too.