Sam,
Yes, that letter is standard. Hopefully yours will go faster than mine did - I have a feeling they delayed on mine because at the time I applied I wasn't yet living with my partner for 2 full years.
I actually sent very little with my application. It essentially included the application form itself and the council tax bills, bank statements, etc. that proved cohabitation. From what the officer in Liverpool told me, that's all they're looking for. So long as you have the number of pieces they asked for (between 10 and 20 pieces, depending on if they're in both of your names), then you should be okay. Insufficient evidence is the only grounds I can think of for being refused, since that seems to be the only requirement.
Best of luck! I hate waiting, personally, so the wait for that approval, followed by the wait for my boyfriend's Canadian Immigration approval, is near killing me. (BTW, if anyone is at all interested, we're at the last stages of waiting for the immigration approval. I figure another couple of weeks, maybe, provided there aren't any delays. Then we can book a flight and go home!)




