iMac is many light years ahead of PC ...no point of discussion. The only matter is the low quality control in China which drives most of the customers to buy an extended warranty to avoid troubles in the near future.....but Apple should have taken care of this issue, this is my opinion.
Maybe, 2012 iMac 21.5 inch are better manufactured, not many quality issues...
2013-2014 iMac 27 inch and 21.5 inch will have some new components installed but low QC will remain a major issue!
As a Mac owner I find what you say about Windows PC absolute nonsense. Windows is a very competent OS in its own right - fact. If you are prepared to pay you can also get some pretty decent hardware. Your posts will be far more effective if they have balance.