I love it as a midi. The others to me look nice, but the midi with boots looks Fab.

If you remove the sleeves, I worry that the armhole will be too big or just never sit or look quite right. With a hem hack, what you see is what you get. Thus, my vote is for the sleeved midi.

Another vote for number 4. The long sleeves just make this dress special. What a great dress!

I also like it best with sleeves, though if you already have several winter dresses and I think summer is your dominant climate yes? You could also consider shortening the sleeves to elbow or 3/4 though if you don't get a lot of transitional weather I don't know how useful that'd be. Just throwing the option out there. I like DesmoApril's suggestion of having the black band seamed out if you shorten the dress.

#4 looks best to me. As others have said a high neck maxi silk dress would not get a lot of wear in a very hot summer. Plus the sleeves add to the look of the dress.
You look gorgeous in the dress.

Thanks very much to everyone who took the time to make comments on this decision. I think the midi votes have it! But I am going to think about this some more. If the forum had come in with a strong vote for the maxi version I was going to hack off the sleeves this weekend so I could get some wear out of the dress before the weather turns. But now that I am leaning towards the winter midi version I have some more time to think about it. Cold weather is still at least a couple of months away. I am strongly influenced by DonnaF's comment that when you hem up what you see is what you get, but if you take off the sleeves it may never look quite right. The high neckline worries me. Smittie is also right to say that the bodice is clingy for warm weather (it is also lined). I still think I would get some wear out of the maxi version on cooler evenings in warm weather. And as Aida says summer is my dominant season. Re Desmo April's great suggestion to take out the middle and shorten the dress or divide it into 2 - I should have mentioned that the print on the back of the dress is an interesting long cross (see new pic). And I am reluctant to lose that. My niggling doubt about the midi version is cutting through the print at the front and what Aliona said ie to the effect that the dress is more "standard" in midi form. I actually do have another winter dress that is similar to the midi version, so that comment does resonate with me.

Decisions, decisions! My only decision for now is to continue procrastinating. But I will report back when the deed is done!

By the way, if I had hacked off the sleeves I was not going to waste them. I was going to turn them into fingerless gloves. I thought that could be quite funky