Actually, I have been using Translit.ru for a while and it's great, very intuitive -- in fact, perfect for me (Russian is not my native but I'm quite proficient). I would love if the Microsoft's layout was the same, as had become a standard for translit over the years.
Instead it's awful, clumsy, unpredictable.. just irritating. I'm typing on it for more than a month and still can't get used to it. For example, delaying the appearance of the letter just because other keystroke might follow.. It's disturbing, there's no response, it breaks up the flow, and even if you don't press it twice automatically, the next is often interpreted wrongly.
I don't know the exact algos of either but it looks pretty straight forward to me. Or is replacing the letter already on display inherently not possible in the OS outside of Office environment?
For now.. JUST FRUSTRATING. I'm talking to my friends with latin characters just because using that layout takes the joy out of the conversation.