I have not driven a manual 991 but I rented a PDK 911 recently in SoCal and have to say it is an amazing piece of kit. I have PDK on my Panamera Turbo but the 991 is a different experience.
My only gripe was the ridiculously stupid shifter buttons on the multifunction wheel and the pull to downshift/push to upshift pattern on the console shifter. It's sad that only the GT3 has the "correct" and intuitive pattern.
Based on this, if you do go with PDK I'd strongly recommend the sport steering wheel with the shift paddle.
For better or worse, because of the nature of the 991, the PDK just seems to suit it better, IMO.

 

The manual feels more racy on the street and the pdk is better on the track.

 

I daily drove 911s (mostly a 993) in Boston for 8 years, commuting. It's not a huge pain in the a-- but when you are in stop and go traffic daily, it sure is nice to not have to creep along in first gear or be putting the clutch in and out constantly to move a few feet so someone doesn't jam themselves in front of you. My 993 had an easy clutch. The only Porsche I ever sold in terror of traffic was my 87 930 which had a 4 speed and did not like to idle in traffic on warm days, the oil temperatures would start to rise along with my blood pressure. I sold that car in a hurry when I took the job in Boston.

 

I went through the same issue before I ordered my Carrera S. I am a long time 911 driver having only had manuals over the years. I test drove both a PDK and manual extensively and decided that, for me, the manual is simply more fun. The PDK is great and definitely the faster car. BUT, I still prefer the manual for ME.
Only you can decide this - test them both - and for more than a 15 minute drive.

 

Another manual vs PDK thread, meaning it will go 10+ pages with no definitive answer.

My suggestion is very simple - buy a manual. There will be plenty of time to buy PDK later when they no longer offer manual.

 

It's a decision that usually causes much consternation before selection, and lots of rationalization afterward.

The PDK is outstanding, and the 7MT is wonderful. While I've heard a few PDK owners say they miss rowing the gears, I've never heard a 7MT owner say he misses an automatic, and should have gotten a PDK.

I suspect that if you dig down deep, you know what you want, and the good news is that there's no bad choice.

 

You must drive both options and then decide for yourself. I will choose the manual.

 

Absolutely

 

I might use it 90% of the time on the streets, but I'm not sure if with my first Porsche might develop love for the race tracks, but not for the moment yet

 

Sounds pretty logical, I beyond to keep this car for good, so do you think MT will be still fun when I will be in my mid 60s? Mmmmmmm, I guess by those days I will get another car with the newest technology.... I guess this answers my question...

 

Even if it isn't still fun, it will be worth more if they are no longer available.

 

Is the sport chrono still worthy to get with MT?

 

I agree 100%
I hate automatic sports car but PDK is a whole different experience.
Being a manual car fan myself, I will not buy another manual Porsche.

 

It you want the automatic rev matching it is. Otherwise, probably not.

 

Don't know where the OP lives? But if it is europe, a MT is for daily drivers, a double clutch for high end sportscars. For me a MT detracts from the sportscar feeling and experience as the PDK allows for more driving envolvement. Let me clarify with an analogy. Golfers amongst us know that we "play golf" and not "play golfswing". We aim to "drive a car", not merely "shift a car". The aim is to master driving as a whole to perfection (utopia I know), and the PDK offers more control over your car. The MT has more time witch the clutch open, hence less control.
In short, PDK for more control and driving envolvement, MT for shifting envolvement.