I'd do one BIG window. You will NOT regret it - it will make your kitchen.

Can you switch your sink and DW? If your range is to the right of the DW, the DW is in your prep zone, which isn't advised. Of course you'd want your faucet to be centered under the right window, so you may need to tweak your drawer bases. I'd eliminate the 13" drawers which will have very little room in the interior of the drawer itself and use a larger sink base.

I think it could potentially be an issue, although when I've worked in this situation, I have tended to look "through" the mullion by focusing past it. But you do have the opportunity to change it, so it's worth considering. One other possibility is to center the sink under one window rather than the pair. I don't know if this layout would work, it makes the landing next to the refrigerator a bit tight. It utilizes the same cabinets and shifts the sink slightly (It switches the drawer bases). Or you could just switch the sink and the DW depending upon where your range is you may want to do that anyway.

Before we put an addition on the house, I had crank casement windows
with the center mullion over the sink. I don't recall thinking about it. In
any case, I'd agree with mayflowers' suggestion to move the DW to the
left of the sink. Since the faucet is off-center, I'd put the sink off
center by 1.75", put an 18" trash pull-out to the right, with 18"
drawers beside that. If there is a trash pull-out on an island, then
you could have 36" drawers for dishes.If you are using custom
cabinets, the sink could be centered with 18" trash pull-out, and 19.75"
drawers. The slot on the left could house cutting boards and sheet
pans.

Off center:

The mullion wouldn't bother me. We rent a place every year for a few weeks that has the sink like yours and I've never thought about it. I do like the idea of one big window though. If you do opt for different windows, go that route!

And unless you have an island directly behind your dishwasher with drawers to store dishes and glasses, I wouldn't move it. It looks like you have cabinets to the right of the sink currently that would hold dishes. If that's the case, moving your dw further away from those cabinets will make unloading the dw a pain to do, each and every time. I know people recommend not having the dw in the prep zone, but mine is, and it's never bothered me. What would bother me is to have my dw far from the cabinets/drawers where my dishes and glasses are stored.

However, if you're the kind of person who has people come in while you or others are prepping and open and close the dw a lot, then you might want it out of the prep zone.

I have a center mullion and never thought about it being a problem. What I would want for sure is a window I can open on a nice day. The idea of an unobstructed view sounds nice if changing the window is in the budget, but having a mullion is that big a deal.

Thanks for the great suggestion. Just to be clear. The cabinets are ordered and so are the appliances. So there is very little leeway to change the actual layout of the cabinets or appliances. The only variable I have to play with is the window layout :(

I have a nice large sliding window over my kitchen sink, so I have a center divider lined up over it. While I have learned to ignore it, I think it would both look better aesthetically and function better for viewing if that center divider were not there. I agree it's not the end of the world if you can't change it - but if you can and it doesn't break the bank, I would. However so many others here have already weighed in saying they have it and they don't even notice it. So this is going to be one of those deeply personal things only you can answer.

This really doesn't have any bearing on whether it would bother you, but is another point to consider - how old are the existing windows? I know that saving them saves you money in the short run, but if you are reinstalling older, less efficient windows you may be literally throwing money out the window in the form of heated and cooled air.

Actually in the drawing I did I just switched the position of the two drawer bases you already have.

@Jennifer: The windows are less than a year old. They are marvin Ultimate and very energy efficient (that is why we chose them).

@palimpsest: Ah now I see it. Let me talk to my contractor about it. I think it would be difficult to center the window exactly by just switching the drawers + it would increase the distance between the dishwasher and the upper drawers where we plan to store dishes, but definitely worth thinking carefully about.

If you like your windows and they are new...keep them. I have a two double hung windows side by side. I like the look, but I have a very old house (1925) and my neighbors are just across the driveway, so the center post is kind of a plus. We wave a lot....but it also gives me a sense of privacy in a weird way too.

Plain & Fancy Kitchen - Dayton Ohio · More Info

My new sink/faucet are centered on the window. They were not before and that bothered me. But the "center" of the window does not. Maybe because the view is actually to the left of center. :}

Hm, do you really look straight ahead when you're standing at the sink, or to the side, i.e. wherever the view is?

Is there any way to simulate it in your current kitchen/sink?

The view on the left is definitely the better view. The right looks out to the garage wall. The left looks out in the front yard.

When my contractor was pulling out the existing windows the fins on one of them broke. This made the decision easy. We are going with a single large Awing window. Thanks to everyone for their insightful comments.

So glad to hear it worked out. I have to say, I didn't notice the mullion in my old windows, until it wasn't there in the new ones and I said, "WOW! This is so open!" Funny how that works.

You will love it.