Istanbul - is it stressful?

or fine?

it looks well interesting but I can't really handle vociferous street vending sort of a thing

Depends on which part 

The rich part is lovely 

The cultural part is very busy - similar to Morocco or Tunisia or Egypt etc. Expect to be hassled, grabbed etc

It's a great city though 

I'd love to go back (and visit more of Turkiye) but am a bit reluctant to do so when Erdogan is still in power. My politics is really limiting my choices for travel ...

What Davos said (sort of). Touristy bits can be a bit hassle but in my experience nothing like as bad as Tunisia/Morocco.  The commercial/shopping bit of town is fine and modern feeling though. 

We went last August with friends and absolutely loved it.  We stayed in an apartment a walk into the main parts.  Its beautiful.  As for hassle etc, what someone else said re Morocco.  I felt much safer and less concerned in Istanbul.  Very westernised.  We went with some friends who were same sex marriage and there was no issue at all, they have been a lot and have never had any problems or experienced any homophobia. The bazaar is busy and can get quite hot but its still really interesting. Would highly recommend.

Great city. Three cities in one. Amazed how much of the Roman city left. The bazar is busy get the guide to take you up to the higher levels.  

would recommend it.

One of the worst trips I’ve ever done. Whilst the Hagia Sophia is breathtaking from inside and the blue mosque the same but from outside, it’s a run down and dirty city and tourists are harassed aggressively. Up there with Marseille when it comes to dodgy European sh*tholes.

I've been twice and didn't have a problem with being hassled or cat called. Vendors will try to flog their wares but I found them really polite and friendly. The men are very handsome and there are cats everywhere!

Sometimes I saw a lone women be called to by restaurant reps standing outside their eateries trying to attract customers but it was always variations of "Hello miss, how are you today!" Before they could presumably mention that days specials, the women tourists would shout e.g. "NO! IM NOT INTERESTED!" or similar (no doubt as a reaction to being creeped on elsewhere) and then the rep would look confused then insulted. But the worst I had was a dog chasing me up a hill when I went for a morning run.

(not harassment related but) there was this old guy selling grilled fish sandwiches from a wooden pushcart near the Bosphorous, which were DELICIOUS.  He had a massive q of customers but was appaz not operating with a permit. Every time a cop came near he would hurriedly push his cart and grill into the nearby public toilets and only returned when the cops had left. Everyone just waited patiently for him to emerge from his dunny hideout. The sandwiches were THAT good. Fvck da police etc 

All that does is adversely impact on the citizen Benj. Sad but true.

Istanbul is great, vibrant and beautiful. Full of energy and the dogs diceman refers to were in my experience friendly goofballs.