I'm not the voice of experience by any means, but can share my story as well.
My wife and I took (and passed) the MSF in July 2010 and neither one of us had any motorcycling experience. Not to toot my own horn, but I scored a perfect 100% on the riding test and my only experience on 2 wheels before that was riding mountain bikes. Keep reading though...there is a catch.
So, I knew it was wise to buy a 'cheap starter bike' but several wiser friends told me to skip the prerequisite Ninja 250s or 500s and just buy a used 600 for a few bucks more. They told me that the 600s had much better suspension and brakes, and that they rarely lose much value so that I could sell it in 6-12 months and basically break even financially. Well, that sounded pretty good so I spent $1800 and bought a 1992 Yamaha FZR600. What they don't tell you is that older carburated bikes are actually huge piles of crap, particularly if not well maintained. That bike was hard to ride, unreliable, and cost me several hunderd bucks in unplanned maintenance. The powerband was incredibly inconsistent and all my buddies just said it was due to the carbs...so deal with it. The bike ran out of gas on me twice and the clutch cable gave me no end of trouble, and the chain broke once while I was riding it. I sold it (and pretty much broke even, which was great) but never really spent enough time on it to get good riding experience or to feel comfortable that it wouldn't strand me. That is the truly dark part about older bikes if you ask me.
Just a few weeks after I bought that Yamaha, a good friend of mine offered me his nearly new Triumph Daytona 675. I knew that the bike was poor for a beginner but it was a chance to pick up a nearly new 'keeper' class of bike for about half price, and from a great friend who was the original owner. I literally jumped at the chance. On day two of ownership I rode the bike 250 miles across the state and learned why he no longer wanted it. That sum-bitch is the least comfortable bike ever made. Everything on it worked perfectly, but I didn't really want to ride it after getting it home (for a while).
So, now I had a used/old/unreliable early 1990s bike that was comfortable and a nearly new modern bike that was borderline unrideable due to lack of comfort. Neither bike was ideal to ride and learn on, so I didn't get much riding in that season at all. The next season I sold the Yamaha early on and bought a 2002 Honda CBR 954RR, which I currently own. This is a phenomenally comfortable sport bike, and I really do enjoy riding it. However, I'm learning again that older and not well maintained bikes have their issues, despite the Honda being one of the more reliable brands out there.
So, what is the point of my story? Make sure you get a bike that actually meets your needs. There are huge differences between bikes and I'd recommend buying the newest and best cared for bike that you actually want. I'd recommend test-riding several since I can assure you I would have never bought my Daytona if I had ridden it even 10 miles (and it didn't come from a friend). The more comfortable you are as a new rider, the more you're going to learn and the more fun you're going to have!
I'm busy working to sell my Daytona and pick up a Monster 796 so that we can have fun on bikes and really enjoy the lifestyle. Coming from a world of high performance cars, power was never really the issue for me since I'm used to respecting that, but being comfortable and confident is a different issue...and I'm still working on that. I hope you were able to make a good decision and buy the bike that is right for you...keep us informed as to what decision you made and good luck to you!