My two kopeks…
First, I’m not going to quote anyone here. (Although I'm tempted to (you know who I'm talking to!))

I will attempt to simply reply to the OP’s subject, “Russian Girls Are Amazing!” and relay my own observations from my experiences regarding the other issues discussed on this thread. Take it how ye may!

To the statement, “Russian Girls Are Amazing!” Yes, they are and no they aren’t. It really depends on how you wish to describe amazement. Yes, overall, my Alla completely amazes me. Life with her is filled with more surprises and wondrous events than I have ever felt before her in a past relationship with any local girl. These traits that make her this way could be found in a woman from another country, besides Russia, I’m sure. It just happens to be Alla is from Russia.
Neither of us set out to find an international person to marry following our past marriages. To be honest, I thought the idea was insane at first and so did Alla. I’m not old (well a little maybe)

, fat, nor bald! I wasn’t seeking a trophy wife and Alla wasn’t seeking a sugar daddy. We were two people from far away places seeking love. We just ended up on the same internet track waiting for our trains to collide head on!

A little of how we got to those tracks...
After Alla was ready to look again, she tried, naturally, in Kazan’. What she found were men that fit in these three categories:
- Sexual relations only (Already had a wife and looking for a mistress.)
- Unwilling to be a father (Willing to be a husband only if the kids stay at grandma’s. If she wants to see her children she can go visit them when he is at work. IOW, he really only wants her to be in his bed every night.)
- Willing to be a husband and father but unable to earn an income to support the family.
After several years of living manless and feeling older, she decided to try an ad on the internet. She considered getting older would only make it even harder to find a nice man. She placed an ad with the hopes of finding a man from Germany. (This was because she had college and theatre friends that had emigrated to Germany and were very happily married to Germans.)
I, on the other hand, was in America, dating my 20th or so “cookie cutter” divorced woman that only wanted to tell me about her horrible, worthless, past husband and how many pills she takes to keep her stable albeit emotionless in everyday life. None had sparked anything in me other than my desire to run out the café as quickly as possible. I had found these ladies on the internet via Match, Yahoo, Cupid, what have you. I didn’t know any single women and had no network of friends that could assist me. The internet seemed my only valid option.
One day, I received a letter from a girl in Russia. It was an obvious scam letter but it made me curious to international dating. I sent a few form letters and photos to international dating sites to see what might happen. Within a few weeks I had many e-mails, but they didn’t seem sincere. They appeared staged and I suspected it was the people working at the service answering me. I set up a few e-mail accounts and made a few phony characters up. Sure enough, I received similar letters with only the names changed. I also found it curious if I said I was a physician, the girl was far more inquisitive than if my occupation was a retail store employee. I had feared this idea was not going to be very viable!
After a few more months, I received a letter from a lady in Kazan’. She told me she was an English teacher and a former manager of a dating service. Her name was “Ol’ga” (she is no longer living in Kazan’ and I do not know if she minds her name mentioned). She said that she had saw one of my ads and decided to write to offer some advice and assistance. I asked her what she felt she could do for me. She said she had a few ladies that were acquaintances of hers and were seeking husband’s abroad. She asked if I minded her showed my photo and profile to them. I said, sure. Also, “Ol’ga” sent me some photos and profiles. It was here, I saw Alla’s photo and profile for the first time. I inquired about her. At the same time, Alla happened to be visiting “Ol’ga”. She saw my photo on “Ol’ga's" computer. “Ol’ga” was responded to my e-mail to say Alla was not interested in an American. Alla asked, “Who is this man?” “Ol’ga” said, “Oh, he wanted to know about you, but I am telling him you are not interested. You want a German man.” Alla said, “I know what I said, but this man has kind eyes, ask him to write me to my e-mail. I like him!”
Well, Alla and I began corresponding and calling each other. After a few months of becoming growingly amazed with her, I tested her by saying I was quite poor and afraid she might need to work very hard if we were to create a family. Alla’s response was, “Would you do all that you could for me? Would we live in a flat and not on street? Would you love me as you're only wife and my children as their father?” When I said, yes to all, she responded that money was never her need. All she needed was comfortable shelter, a feeling of security, and love for her and her children. “If I must work to help provide these things it is okay!” Well, that made me even more amazed. She was loving me for me. It was obvious this girl was no gold digging green card seeker. It was with this that I decided to step it up and meet her for real.
Without going on and on, for the next four years of our personal history, I can say that, for us, we earned each others 100% trust after my final visit that lasted one year. It took living as a real family, under Russian conditions, to feel our love grow to a complete mutual understanding and solid faith. Visiting like a tourist the first two times were, truly, useless for us. I’m not saying it can’t be done. (Not everyone can walk away from work, family, etc. for a year.) But for us, we needed the true practice, this test, to be certain creating a family with each other was truly what we wanted. It solidified our bond to each other and our families. I have no doubt or mistrust. If either of us did, we would stay single!

Thanks for sharing about your personal journey. Very interesting.
Obviously you both took a long time to know each other and no one can say you guys jumped into the an engagement. Four years is a long time, especially when it's a long distance, multi-country romance. That's a long time even if were talking about dating someone from your own town.
And you living with her for one year is very unique...and I wonder why so long but that's really your business. Clearly very few of us can or would want to spend a year in an environment that does not resemble the ultimate world we must share with our wives down the road. And if you fail, you've given up one year and all the associated sacrifices you made. That's a lot of risk to accept, in my eyes...but then, you're a younger man so maybe you see it differently.
Anyway, I can see that you have looked fully at half the puzzle by being with Alla and observing her in her home environment...but I don't know that you're ultimate success is assured until you both address the other half of the puzzle...marriage and life in the USA. That's the tough half...so even with that long year together, coming to America is radically different, so all bets are off. Yes?