I am (was!?) thinking of getting the 70-200 f4 IS lens but I can get the Canon EF 70-300mm F4-5.6 IS USM lens for 1/3rd the price of the 70-200! I know it may be coming down in price since Canon said they are doing a L version of this lens soon to be released.

Which one would you choose? I have heard such great stuff about the 70-200 plus is weather sealed and the 70-300 sounds a bit harder to use to get the pics you want - but then it has the extra length....