Nanjing -- 

Positive: 

- Fairly large expat crowd, subway / metro is very convenient for getting around town and cheap, people are pretty friendly in my experience, tons of options for food (from mexican, italian, subway to lots of cheap chinese food), great bar scene with very cheap drinks and western food (Ellen's Basement, Sancho's), 1912 bar street is cool but drinks are expensive, Teacher salaries are pretty much near first-tier city level. City isn't that big so can get used to it fairly quickly.

Negative:

- Not a whole lot. Taxi's start at 10 yuan and then add 2 yuan each time for some surcharge, Also not always easy to get a taxi but like previously mentioned subway is super convenient.  Very hot in the Summer. It's one of the furnaces of China. However, buses, transport all use AC. Even your regular hole in the wall Chinese restaurants will usually run AC during the Summer.  Really not much else I can complain about. 

Suzhou

Positive:

Large expat community

Subway just opened

20 minutes by train to Shanghai

A lot of good bars - Local and foreign style

All kinds of food + Sherpas for online food orders

Supermarkets with import sections

Very beautiful city

Good expat food street and supermarkets in SIP - I recommend living there

Friendly people

Negative:

Rude taxi drivers, but I guess they are everywhere

Sometimes the taxy drivers won't go to the city center, but the new metro should fix that problem

I don't have a lot of negative things for Suzhou. It is by far my favorite Chinese city.

I have lived in Suzhou for 3 yrs and traveled to many cities in China during that time. I am always happy to return to Suzhou as it now feels like home, even when returning from the U.S.

The positives are; Easy to get around town with the subway. Many english speaking residents. People are friendly. Low to no crime. Clean streets and beautiful gardens. Imported foods are readily available. Not too crowded compared to other cities. (only 6 million people)

Negatives - Really very few, plenty of foreign restaurants, but many are only a Chinese representation of what that food is (like Chinese food in America)

Suzhou is overrated both by the locals and by the expats.  Somehow, somehow, with all changes over the years, it has become really soulless.  It is modern, new, etc., etc., but where is the real city center?  It just doesn't feel like a city...it feels like a huge agglomeration of large housing complexes one-on-top-of-the-other.  Suzhou people are indeed friendly, at least compared to where I am now and it has all the amenities of a large, almost world-class city.

Nanjing just rocks.  It has charm, tree-lined boulevard, tons of history, mellow folk, mostly, an interesting history and combination of old and modern.  It is just as easy to get around as Suzhou and it really oozes charm.  The restaurants are great.  The deterrent?  The weather...hot, hot summers, and cold, unheated winters, about the same as Suzhou.

I once left Nanjing for Suzhou and regretted it very much.  It's all personal choice, I guess.

Sausages and underwear hanging out to dry...a common site to behold in the laneways of Nanjing

Nanjing's better! More subway lines, and there's a vibrant city centre near Fuzi Miao with a ton of touristy things to do. 

Suzhou has kinda sprawled all over. As one poster said, it feels soulless. 

both of these are good cities with a good chance to grow and have many opportunities in the future.and one of them was the former capital of China.

I've been to both Nanjing and Suzhou and Suzhou definitely wins!

It's awesome, so much to do.. It has a soul! It's a shame I am not living there right now due to personal reasons but frankly I would love to move there and live there for a month or so... But I like my little City where I am right now, it's just about right and comfortable/..