Interesting george, I wonder how the wieght compares with my Epic which i find real heavy, with lots of weight in the neck...so it can be hard to balance without a good strap and some tweaking -  
How long have you had your alembic george? Did you get it from USA or over here in UK?

Id never heard of birch in guitars either Bill...and Ive looked at hundreds of Alembics -  
It has to be quite a rare wood type? - makes georges bass that bit more special. (more special than Series 1 alembic!LOL)
Rob

I have an old Seagull acoustic guitar that is made from birch. Probably built in 1980, it has a serial number of 973. For a cheap guitar it actually sounds pretty good....
 
JP

Yep, they'er usin some crazy woods for cheap guitars these days - I seen one thats made almost totally out of little strips if bamboo!! all glued together!