some info here,
http://www.gamasutra.com/features/20051228/sherrod_01.shtml
from what I have seen, dxt1 gives you the biggest compression
but no-alpha-channel, seems it is perfect for
most of your general texture needs,
dxt3 and 5 gives you an alpha-channel and the compression
has better quality, but the alpha is more detailed in dxt5 than in 3
Paolo.
http://www.gamasutra.com/features/20051228/sherrod_01.shtml
from what I have seen, dxt1 gives you the biggest compression
but no-alpha-channel, seems it is perfect for
most of your general texture needs,
dxt3 and 5 gives you an alpha-channel and the compression
has better quality, but the alpha is more detailed in dxt5 than in 3
Paolo.