I've seen SSDs perform faster than that, I mean the windows boot screen was there for 1-2 seconds where on the one I've seen before you didn't even seen it it was so quick
not by much, current desktop HDD"s use 3-6 watts, i bet current laptops use less than that. SSD's would be less than 2 watts, but that doesnt make much of a difference.
what extends battery life is lower the cpu voltages.
EDIT:
this thread also belongs in the Hardware\Software forum.