Not really, say your shooting football. You nail your exposure and wb. You stick the card into the laptop and wait for photomechanic to ingest your photos whilst you carry on shooting. The jpegs are only a couple of MB each so you can breeze through them all at great speed just cropping and checking they are sharp. You can just caption and fire. All the processing is done in camera; so essentially you can have your best 20 shots FTP'd before the fans have even left the stadium. You could always do a quick levels in Ps before you FTP them if your worried.
Take RAW files and you can't just stick them into photomechanic (you'd have to use lightroom which has a rubbish clunky interface compared to PM and you'd have to apply that preset and even if you've got a new laptop beside you it's going to take you much longer to import the raws with the preset and caption in lightroom (filling your HDD and RAM with 10mb images) than just captioning in PM with a pre processed file thats 2-3mb in size. Essentially my point is that with sports photos you don't have time to mess with them.
There is digital photo professional from Canon if you need somethign lighter...
And if you have a new laptop it doesn't take that long.
My 2 years old Vaio (2,5GHz Core2Duo and Intel SSD) doesn't take too long to chew through the 5D MK II's files - it will take a while if its 300 files.
Take a new laptop with an i5 or i7 and a higher clock speed and you can flick through the RAW's in no time - besides, even the 1D MK IV only shoots 16MP -> another gain.
I can't see RAW's being that much of a problem.