Gave it to a friend after a few months, but yes, I owned an iMac.
You need to keep in mind that the Mac Pro is a workstation using workstation grade parts. As such, it's substantially more expensive in comparison to the iMac when you compare specifications to specifications - but less expensive in comparison to workstation offerings by HP and Dell. I actually went with the Mac Pro because it was cheaper than other vendors, which I'm sure you'll all find somewhat surprising.
It all depends. I have multiple monitors on my desk, so using an iMac as my primary computer simply wasn't an option. All things considered, I think you'll be perfectly fine with an iMac. It's really a respectable machine with a fantastic display that usually costs a grand if purchased separately. If you want to save money, buy an iMac. If you have the cash to spare and think you need the extra flexibility, buy a Mac Pro.
But for you, I'd recommend the iMac - after they undergo a refresh with Intel's new CPU architecture.