Paul is right. Most apartment buildings in Moscow, even ones that look elegant or high-end on the outside (pre-revolutionary or Stalin era buildings can often look quite impressive outside if well maintained) will still have a horror show for an entrance. It's what I call the podyezd ("entry hall") problem. Here is a nice intro to the podyezd for those who haven't experienced it:
http://findarticles.com/p/articles/m...7/ai_110531531

I've been in apartments that are virtual palaces inside. They wouldn't look out of place on Park Avenue in NYC. But to get to the apartment, you have to walk through the urine-infested hell hole that is Russia's version of public residential space. It's certainly one of the few remaining truly democratic aspects of Moscow society, which is increasingly fragmenting along lines of wealth. Everyone, from the rich to the bus driver, must negotiate the podyezd. I have friends in Moscow who are investment bankers, prominent journalists, successful artists, even one of the top executives for Russian state television. None of them have an entryway comparable to even a middling, down-on-it's-luck Manhattan apartment building.

The units offered by Evans (one of the companies I suggested above), tend to be in slightly better maintained buildings, but there is no guarantee.

Hence, why I said in my original post that renting an apartment is for the adventurous. For me, it's part of the charm of Russia.

On the visa registration question, I've used GoToRussia many times, and also used other services, and I've never had a problem. The whole visa registration system is truly bizarre and one of Russia's more 3rd-world-ish aspects, but as long as you do what you're supposed to do and bring photocopies of your visa and passport, you'll be fine.