@whimsey21
They're very close together.....
I'm staying in the Citadines City Centre next month, all the reports I read suggest it's ideally situated.

It also looked pretty well located to me based on the map, but I wasn't sure if there were any extenuating circumstances (traffic, bad neighborhood, etc.) since I haven't seen it recommended...

For the record, the Mercure in Renmin Square is pretty reasonable. The rooms are small but clean and comfortable, and a lot cheaper than the Sofitel. Getting a taxi can be a chore (although this might be a problem through out Xian; I don't know). One evening we couldn't find an empty cab for a good 15 minutes, when finally a very rustic-looking rickshaw pulled up - basically an electric scooter with seats. We said "what the heck" and got in. It was the bumpiest ride (no shock absorbers to speak of, no padding on the seats), the velocity was verrrry slow when going uphill, and the driver got lost - but he asked around and eventually got us to within a block of where we wanted to go. Not all the way, because his battery died! I still wonder how he got his rickshaw back home.