Need your 400mm Help

I need your help. I'm evaluating a Canon 400mm 2.8 IS lens. OMG the weight difference between this older (Mk I, I assume since it is not a Mk II) and my 300 is more than a few pounds. Really have to steady it and the balance when moving around with it on my shoulder was very different. Mechanics out of the way, it was a pleasure to shoot with.

Here are two sample images from this evening. There is a definite vignette but I'm not sure thats a bad thing. I don't believe it was the stadium lighting, though that could contribute. I'd be trading my 300 and some cash. On the outside this is definitely a used lens. The lens hood doesn't have the screw to fasten it down so it needs some work, but the glass appears good and thats the critical issue.

A new Mk II would likely be faster. lighter and sharper (maybe?) but would be 2.5x the price I think I'll pay on this with the trade.

I was shooting RAW and saved these in Photo Mechanic to jpg at 50% +/- quality and 800 px. No post processing was done otherwise. From those of you who've studied some of these lenses, I'm looking for opinions on the lens and the deal. I am not what I'd call a "pro" so it's a hobby expense and not something that will pay a return in X months but I don't want to squander money either just because I don't expect to see the lens earn its price.


Thanks in advance.

These look underexposed and suffer a great quality reduction from web resize. Do the full sized files appear sharp to you?
Hard to give opinion on the deal without knowing the asking price and age of lens. These go for $6000 or so depending on condition.

Once I took off the rain cover and looked at the lens, it's an older copy and isn't serviced by Canon. It isn't an IS lens and I'm going to have to pass. But thanks for looking.

Well those are still serviced by repair shops and the price should be commensurate with its older age.
What was the asking $$?

He was looking for my 300 2.8 and some cash. He really doesn't know what he has and I was working thru a mutual friend. I believe my 300 is worth more than the 400 at this point. But the 400 isn't up to my standards so it is moot.