I'm sure that 6% (give or take; based on a rough estimate of Mac users) of those reading this will think you've received a superior computer. There's a lot of opinions on this and sometimes this discussion comes to the shedding of blood.

I take a less serious view. Let others lose their lives to hate, anger, discrimination, and rock throwing.
I've used both platforms extensively, but would not consider myself a power user. I'm certainly better than most (that's not saying much) and am the go-to person for resolving computer issues before going to the IT professionals (the "geeks"). In my opinion, Mac gets a bum rap by PC users. It performs well and is as easy to use as a PC. It didn't take me very long to adjust to not only the Mac's idiosyncrasies, but to be able to work both platforms side-by-side without being frustrated with their functional differences.
For
most computer users, either computer should serve their needs. The applications do the same things. They both go basically the same speeds. They both offer the same storage capacity. [This list goes on.]
Are Macs "easier" than PCs? I don't think so. For example (in addition to personal experience), Macs had been the standard computer for schools because they were perceived as easier (maybe they were "way back when"). All the local school districts around where I live have converted to PC usage for both teachers and students as the standard. The reasons? Ease of use and "realistic" preparation of students to what they will be using out in the real world when they graduate from school. My wife is a 21 year veteran school teacher and these are the reasons given her when her school district made the change to PCs six or seven years ago.
Some (not many) will emphatically argue that Macs are
THE MACHINE for anything related to art development (such as desktop publishing, video editing, etc.). From my experience, I've had no problems whatsoever in running these applications from a PC. I believe this to be an old argument from the "dinosaur" era of computers that still gets healthy/unhealthy banter. If there truly is a Mac benefit in these areas, my guess is that it is so slight, only upper-end professionals would be able to tell the difference and be able to quantify their position from education and experience. I did professional desktop publishing for many years (not the top-end stuff) and the PC served me for 100% of everything I needed to do.
Macs are susceptible to viruses; just not IBM viruses. Again, going back to "percentages," those "evil doers" who write viruses write them for the biggest target (that would be PCs).
More software is written for the PC, again due to the market share, but most people wouldn't be effected by this because what most people want/need in applications are available for the Mac.
With all this being said, I'm a PC guy...period. In addition to enjoying using them, I have also branched into modifying/upgrading and building PCs from the ground up. But on the other hand, broadening one's knowledge and experience is always a good thing, thus my 7 years' experience with a Mac was both valuable and beneficial...it's made me a better person and will open more doors in life. If things were different, could I happily live with a Mac (if no choice was given)...absolutely! For me, it isn't that big of a deal...just my preference. But my preference is shared with an overwhelming share of computer users.
Ultimately, more power to anyone who choses to use whatever brand of computer they have chosen. They will be better because of it.
Personally, I'd either sell the iMac and use the money to upgrade aspects of my PC or maybe keep it to learn how to network a Mac to a PC network and other experimentation purposes.