All on auto, as I believe it is a better solution than a single exposure across such a wide span. Then it goes through Match Total Exposure in LR, then PS usually does a very good job at equalizing exposures on its own. Of 17 original exposures, however, 13 are at the same speed (1/100s), two are at 1/80s and two at 1/125s. Hardly more than ⅓ of a stop difference.
By the way, I still do not see what you are seeing.
P.S. Note to self: do not try to sell anything to Dave, he would be a picky customer 
Ah ha..
Now I think we are getting somewhere, it is that small but slight variation in exposure I think and/or possibly how LR Match Total Exposure (whatever that is, as I don't use LR) that may be causing this very slight, but to my old eyes still noticeable variation and also the reason why it appears symmetrical, as it is probably a software generated phenomenon, which for your average Joe wouldn't amount to a hill of beans, but for those of us (well me really) that get far too retentive about these things, it is something that can be easily cured at the point of capture, by setting everything to manual and allowing absolutely no variation what so ever to creep into the shot and that you then have to try to repair with software - try going fully manua Slobodan, you will be amazed and it really is very easy to do.
So not really trying to tell my granny how to suck eggs here or anything, I have written this for anyone wishing to read this info, but this is what I always do for my pano work and it works for me absolutely perfectly every single time (well, nearly
).
1 - Never ever use a polariser.
2 - Use ALL fully manual settings and most definitely including WB.
3 - Level your tripod head to the base plate of the tripod before commencing.
4 - Rotate your camera into the vertical orientation.
5 - Work out where you are going to start and finish your series of shots and then add at least one more shot than you need at either end, so you can then crop out any lens softness or vignetting at either end of the shot.
6 - Select your f-stop that gives you the best detail, such as for your shot Slobodan, I would have gone for something like f/8 as the subject is quite distant and so DoF shouldn't therefore be a problem, so I woud go for the nearest I could get to the sweet spot of the lens.
7 - Having now lined up your shot, select the most dominant feature or the thing of most interest in the shot and then set your hyperfocal distance to work on this part of the shot - I use Live view fully magnified to achieve this.
8 - Now meter the scene at your chosen point of interest and manually select the appopriate shutter speed and ISO mix.
9 - Use a cable release.
10 - Take a single test shot and quickly check that your histogram isn't climbing either wall.
11 - Take a shot of your finger blurry in front of the lens (so you know back at the computer the following shots are part of a pano set).
12 - Go into mirror lockup and live view mode and rotate camera to beyond your left most shot so you can crop it off later to remove any of your lens edge effects, such as softness or vignetting that would appear on the left of the shot if you left it in.
13 - Make sure buffer is empty (no winking lights etc) before you begin as you are going to be shifting lots of data around in a very short time.
14 - Standing behind the camera and looking at the screen and with your remote in hand and prepared to work very quickly, take your first shot.
15 - Now quickly but gently rotate your camera half a screens view of the scene to the right as seen through your Live view screen, let go of the camera and count one thousand, two thousand to let the camera shake subside and take your next shot.
16 - Repeat step 15 through to the end of pano set, including an extra shot past where you want the pano to finish, that again will allow you to crop off any soft edge or vignetting effects of your lens on the right of the shot - I also find that I am holding my breath throughout this whole process, which of course is something you don't need to do, but it does seem to make me concentrate on what I am doing and makes me do it as quickly as I can.
17 - Take another shot of your blurry finger to show that the pano set is complete.
18 - Learn to do all this from start to finish without thinking in well under a minute, whereby the shooting part of the whole minute for say a 10 shot pano set, should only take about 16 seconds of your full minute - yes I know, it does indeed take much practice to do this fluently, but once you get it, it's a breeze
19 - Back at the PC and through Bridge, highlight all the files of your pano (without the blurry finger shots of course, but all the other shots in-between) and then go to Tools and select Photomerge and then in the large dialogue box that opens, select layout merge as 'Cylindrical', as this is the best merging method, ask Mr Schewe, he told me that and he is correct of course, also tick 'Vignette Removal' tick box, but do not tick Geometric Distortion tick box.
20 - Sit back and watch your creation come to life.
21 - You can now tweak the masks if there are non-aligned ripples in the sea etc or anything else that does not line up quite right, but other than that you can flatten the image and 'save it as' in a ProPhoto 16 bit Tiff for your main working copy, crop off the soft and possibly vignetted parts of the shot at either end that you never wanted in the shot, but still took anyway and also crop out any blank pixels around the edges created by the 'Cylindrical' merge layout process to square off the shot and there you have it, the image is now ready for any other tweaks that you might wish to throw at it and then save that worked version as a second finished copy just in case you wish to go back to your original Tiff.
A ten RAW shot vertical Pano created with my 5D MkII as a flattened but uncompressed ProPhoto 16 bit Tiff, is going to come in at around about half a Gig for the single image file, I even have some huge Pano's on my PC that are nearer to 2 Gig in size, so if you do intend to get more deeply into this, you are probably going to want lots of HDD space and processing power and especially if you start shooting and stiching 20 or 30 shot pano's together. But remember at these sizes, you will be shooting an almost 360 degree pano shot, so you are bound to start getting some interesting geographical distortion effects creeping into your images at those sort of numbers, a bit like using a super extra wide horizontal fisheye lens, mounted onto a camera with a 300mb sensor.
Have fun
Dave
