I have burned some swamp maple and I was not impressed.
I found this on eHow:
Density and BTUs
Swamp maple is considered a "soft" maple because its wood has a lower density than "hard" maple, like sugar and black maples. Denser wood produces more heat, measured in British Thermal Units (BTUs). Swamp maple produces about 19 million BTUs per cord, which is rather low compared to other hard woods. The best hardwood produces up to 29 million BTUs per cord while the worst produces only 15 million BTUs.
Positives
Other than its low heat value, swamp maple has a number of characteristics that make it good firewood. It produces only a light amount of smoke and doesn't spark when burning. It also has excellent coaling qualities, which means that it continues burning as embers for a long time. It is also fairly easy to start burning.
Negatives
Besides the low heat value, swamp maple only has one other negative. Typically, softer wood is easier to split. However, this is not true of swamp maple, which is considered moderately difficult to split. Firewood must be split to allow it to dry out and season. Reducing the moisture content raises the amount of heat that the wood produces.
Read more:
http://www.ehow.com/info_8751686_swa...#ixzz2jqCpIpM9
Good luck!
R2B