You will always find people who have negative experiences on any platform and it gets amplified on the various fora. I was a Windows to Mac convert at home in 2008 (at work, in the 90s) and couldn't be happier. I used to care a great deal about fiddling with machines until I realized that what I really wanted was a tool that didn't really get in the way. I drive the machines very, very hard as a software developer/ data engineer by trade and photographer by hobby and generally don't see too many problems on my late 2008, mid 2009, mid 2013 MBPs. I also found that my time being the resident IT guy in the family dropped to near zero, which was awesome for everyone. And really, for my work life, which is spent on Linux boxes while simultaneously dealing with people on Outlook and other office products, this is a great more frictionless way for me to do that. The fact that it blends with my ecosystem of iPhones, iPads, Apple TV is great, but that obviously depends on the system you have of course.
Yep, Windows has come a long way and I really like what Microsoft is doing in certain areas since they chucked out Balmer, but I can't see a real reason to move back, all things being equal. The great thing is that Office on the Mac works great these days so if you need that aspect of Windows, you can have it, for the most part. If you are a fiddler with machines, or maybe you think iOS is for toy computers (there's a convergence of some components of iOS and Mac OS X that some people don't care for), probably Windows is what you want.
OP, I think you will like working in OS X. While entirely personal and subjective, I find the industrial design of the Macs to be second to none and I think OS X is generally really elegant. From your other concerns, I like OmniPlan and OmniGraffle much better than I like working in Project and Visio. I say give it a go!