For my second lens...24-70 2.8 or 24-105 f4?

In my previous post concerning which lens to get first ( http://forums.dpreview.com/forums/read.asp?forum=1029&message=39050179 ) it looks like my initial thought was correct: the Canon 70-200 f2.8 IS II will be my first piece of L glass.

Although that is a great lens there's obviously the 70mm focal length limitation. So now I'm torn as to which "walkaround" lens I should get: the 24-70 f2.8 or the 24-105 f4. I currently have a Tamron 28-75 f2.8 that I really like, but I sometimes feel like I'm missing out a bit when limited to 75mm (and there's also the issue that it's not sharp until stopped down to f4) so I'm leaning towards the 24-105.

Both lenses still need to be stopped down a little to get sharp which has a greater negative impact on the 24-105, but the 105 has more FL which is a negative against the 24-70.

sigh ...what to do?

So...who else has been faced with this decision, what choice did you make, and how did you come to it?

Who knows? Maybe the 70-200 is my walkaround....

Thanks so much!

P.S. My camera body is a 60D.