Hi,
I am still new to the whole NBE thing, so definitely not an expert, but here is what I experienced:
Kangzhu - I first started with them for a couple of weeks
Pro - it is quite cheap
Pro - It has nice rubber around the edges, so doesn't hurt your chest
Con- I really struggled to keep the pressure which meant that I had to pump every now and then. So I couldn't do anything else
Con - After my second use, one of the airlock bits fell off, so I always had to do a bit a maintenance before I start.
Noogleberry - I switched to NB after a couple of weeks on Kangzhu
Pro - More professional system - definitely better quality
Pro - Suction lasts. I pump and then I can go and do other things and it keeps the suction.
Pro - Bigger sizes (XL and XXL)
Pro - great customer service
Con - Much more expensive
Con - it doesn't have rubber rings, so it took me a while to get used to the cups.
Bad effects = As far as I know, you will have issues with ANY system if you overpump. I suggest you read some of the threads on the forum about NB and Kangzhu as it will give you a better idea of overpumping etc.
All in all, I think both systems can work. If you have the money, I would suggest NB, but it is just because I am lazy and like the convenience of pumping and then going on with my life.
Hope this helps