Heck, if you're going to drop 1500 dollars on a lens you might as well throw down another 500 and get the absolute best.
Yeah, as an owner of the 2.8 L non-IS, I chose not to spend the extra $250 for the IS when I bought it. Looking at the ISO 12233 chart comparisons, I the non-IS is higher IQ. IS wasn't worth it for me given my intended use (sports).
I am considering a move up to the 2.8L IS ii though, mostly for the IQ, and some for the IS in non-sports settings (in lieu of the top end of the Holy Trinity). Time will tell though -- if the kids get more into hoops or volleyball, I'll probably throw that money into an 85mm f/1.8 and some strobes. But I digress...
I don't see the value in the mark i IS, because of the IQ.







