Silverstonev8 wrote in post #12703996
I pulled the trigger on the 70. I just hope I dont regret not getting the IS...
I am now looking to part with my 50 1.8II
I went through the same dilemma you did ... and likewise pulled the trigger on the 24-70 f/2.8L ...
When I first started taking some shots with my new 24-70, many of them were blurry, and I started to get upset. I was used to the "modern IS" of my (former) EF-S 15-85mm. Then, I remembered reading a tip from an old-school photographer on the lens, and he basically said ... Go back to basics, take your time, and (if possible) use a tripod. So I decided to slow down, I used good deliberate technique, and took my time with my shots. Ultimately, my 24-70 proved to be as sharp as my macro lenses in many respects ... delivering superb color rendition ... and achieved results that my (sold) 15-85 couldn't achieve. Heck, in many cases I now prefer using the 24-70 over my macro lenses, for photographing larger flowers and such.
Regarding Image Stabiliaztion, I think a lot of times IS "spoils" you ... in the truest sense of the word spoil ... in that it makes you take shortcuts & rush what you're doing, relying on the lens to be your "crutch" for bad technique. To be honest (except for my 100L), I no longer have any IS lenses ... and I am considering selling my 100mmL that does have it ... as the "non-IS" lenses I do have blow away what I can do with my IS lenses.
Maybe you need IS, and I know a lot of folks do need it for action-type photography ... and that's cool ... different needs require different tools. But if you take your time with your shots, you will get superb results with your 24-70.
In the same way, my outdated 180mmL macro and my MP-E 65mm macro may not be able to keep up with my "modern" 100mmL IS out in the field ... as the two outdated macros have neither IS nor super-fast AF ... but when I slow down, take my time, and put the elder lenses on a tripod ... the elder non-IS lenses achieve results that my newer 100mmL can't do 
Cheers!
Jack
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