Firstly, when I initially came to China (with my family) I fully intended to stay here permanently, however, due to the Education system and having a young daughter I now intend to return to UK in 9 years time, (when she is UK high school age).

My original plan was to keep working, saving and investing, a bit like what I imagine Americans do to save for retirement. Also the UK old age pension can be drawn worldwide (depending on how much you've paid in iirc). My major difference is that I don't want to retire so long as I am able to work, (I view it as the first stage of death). However, I'm already drawing a nice pension. The second part of my plan would of been to sell my UK property and use that to pay off my Chinese mortgage and use the remainder to add to my portfolio.

Having said that I never envisaged trying to get a permanent visa, and about the only benefit I can see is not requiring to renew your visa every year, and perhaps (not sure on this one) property rights may be different.

I can't see the reason of getting one, unless probably if you are married to a Chinese.  To be honest, I personally wouldn't want it not even if you offer me millions after millions of RMB.  

There are commercial benefits if you are in business. The banks and numerous other financial institutions will look at you more favourably for certain credit facilities. Having permanent residence rights does not of course mean you have to stay here permanently so people will apply just to take advantage of the commercial benefits. Permanent residence may also create a greater level of confidence for foreign nationals that intend to invest in property. Owning property is a requirement for marriage in many cases in China but renewable one year RP's increase risk. As for retirement, I wouldn't mind investing in a hideaway somewhere in mountainous areas of Yunnan around Lijiang or Baoshan.

Not sure of any legal benefits, but if you're in it to win it, people will stop looking at you as a backpacker.  It also takes more than a few years to develop any meaningful guanxi.  Think about it: how would you feel about an expat in your own country who's just going to leave in a year or two?  Would you do business with them?  Would you offer then a tenure track job?  Staying here proves you are not expendable. 

  I do not see any benefit to long-term residency in China or anywhere on this earth.    I would rather be a citizen in the Kingdom of Heaven!

people confuse a lot of things here;

nationality, citizenship, residency and domicile are four autonomous concepts. a natural person can both be domiciled, resident, citizen and national in four different jurisdictions all at the same, if he so wished/accomplished - even with "no dual nationality" laws - since citizenships and residencies are not nationalities.

please, make sure you understand the legal difference.

next,

a Chinese permanent resident visa (at the time of writing it is not yet a card - it is a VISA and it is stamped into the passport of your nationality.) gets you and possible extended family out of entry/exit hassles - but not a whole lot more...

credit from banks? beyond regulatory guidelines - a foreigner's visa is not the issue. money... is the issue.

housing/hukou rights? again, most visa type can do this as long as terms are met - a foreigner's visa category is seldom a part of those terms.

work/business? you still need a work permit and laws regarding foreign investment apply; you are not a Chinese national.

after Jul. 1., the new version which is a physical card, IF equipped with chip and made compatible with the remainder of public security infrastructure, will allow you to purchase high-speed train tickets automatically, register online accounts that previously did not take passports and were tied to ##digit Chinese id-cards, etc.,

customs and shopping - all else concerned you are a foreigner in China. (those concered that chinese pr requires ceding foreign nationalities may feel relieved now... haha)