Canon 70-200 f/2.8 IS MKI VS. MKII

[NayLoMo6C]

I'm pretty sure this has previously been discussed here already, but I am having a dilemma. I just plopped down $1100 for a Canon 70-200 f/2.8 IS MKI ( used but in almost like-new condition). I bought this primarily because I needed to upgrade my 70-200 f/4 IS since I wanted better bokeh for my wedding and engagement photography.

I haven't tested the f/2.8 I just got yet since my next wedding shoot isn't for another month or so, but I just wanted to ask, should I stick with the MKI for now, or should I resell it and upgrade to the MKII? I got it for really cheap ($1100) and I know that I can resell it for higher ( probably $1400 or so~). Is the MKII THAT much better than it's predecessor as many of the online reviews claim it to be (in terms of overall picture quality)?

 

[snerd]

I can't answer your question, as I've never had the MK1 version. But the MKII is the best lens in "my" bag! 2.8 throughout, internal zoom, and the sharpest lens of any of my other lenses, well, the 24-70 2.8L II is about the same. If you can make money from the sale, go for it!