^^^^To add a little info (for the OP)...The 1.4x version 1 (unlike the 2xTC) is the same optical formula as the mark II TC. The mark II only has the addition of weather stripping (as per Canon product statement) so don't think that the version 1 has inferior optics. I have an original 1.4x TC and it looks spectacular on my 70-200 & 400 lenses.
(another) Free Bump for 'msauk'
I really am surprised that no one has taken this TC yet. I can not emphasize enough that this version I of the 1.4x TC is absolutely optically identical to the version II...and everyone knows how sharp that one is! The version II (of the 1.4x TC) only has the addition of weather seals on it.