Might as well ask a question about something with high-profile criminal trials I've always been curious about:
Had George Zimmerman used a public defender, or Legal Aid or something like that (leaving aside any qualification issues) ... would it have been a slam dunk that he'd have been found guilty? IOW, was O'Mara & West's defense work something many lawyers could've pulled off?
Of course not. And the fact that people attribute the win so much towards highly private counsel is really indicative of just how few people outside of the legal profession truly understand (although, now that I'm in private practice in its my best interest that it stay that way).
Contrary to popular belief, public defenders really are lawyers. They have the same fancy certificates and go through the same training (if not even more). Additionally, they work on nothing but criminal law in a particular jurisdiction (often in front of the same judge with the same prosecutor) and generally with the same time of cases (misdemeanors vs. lower level felonies vs. higher level felonies vs. capital - if applicable). Generally, if you want an indicator of how a particular case will resolve in a particular court with a particular prosecutor, nothing is going to be a better source than the public defender in that court. After all, they are in those courts nearly every day and see those issues litigated in that particular jurisdiction. Furthermore, many public defender office's are structured in a way that when a case proceeds to trial it is assigned to a lawyer who solely handles trials for that types of cases.
Using myself as an example, my first three years as a public defender in our smaller jurisdiction I handled over 500 DUI cases and did over a dozen DUI jury trials, and over 100 bench trials. My office provided me with dozens of hours of DUI-specific training and I attended several conferences each year to update myself on any and all issues DUI. I litigated every issue and had enough trials in the jurisdiction to probably know what worked. I also knew each judge well enough to predict their sentences at trial and each prosecutor well enough to know how good (or bad) of a deal was possible in each case. I'm very confident in stating that there was a point where I strongly doubt any lawyer could have better defended DUI cases in that jurisdiction better than me. When I went to work for Maricopa (Phoenix), I was immediately assigned to a trial group where I did nothing but felony jury trials. While that jurisdiction is bigger, my sole focus was on the criminal trial. Furthermore, at both offices, I had an investigator assigned to me for use at my discretion and I could get indigent funds to get the same wonderful experts which cost a retained client and arm and a leg. My caseloads, while intense at times, were closely monitored as well to make sure I was overworked. In short, I am fully confident in saying that I was capable of trying cases just as well as any private attorney in those jurisdictions.
That said, there are some potential downsides to a public defender. First, while a defendant has the right to counsel, he doesn't get to individually choose his public defender. While most that I have met are quite good at their job, as in any profession there are some public defenders that are either burned out or simply not that great at their job. Whether that be due to poor public speaking, lack of experience, minimal effort, etc. there is some potential to wind up with a sub-par lawyer. Also, not every jurisdiction may afford their public defenders the same benefits and resources that I experienced. Lastly, it's possible to get a lawyer with less experience - since the common progression is to take the lowing paying job out of law school, get a bunch of experience, and take a private job (my path). However, it's also possible, especially in a very high-profile/serious case, to get a seasoned lawyer who was private for many years who took a job as a public defender to get away from the stresses of private work. Those guys have seen and done it all, and are going to be the best lawyers in the room regardless of who else is there.
Going back to the Zimmerman case, the defense there, while incredibly controversial and interesting, really isn't that legally complex in that it is a standard self defense case. Zimmerman had many facts on his side (you'll note on this board most lawyers correctly predicted the verdict) and in my opinion any competent attorney, public defender or not, had a reasonable likelihood of achieving the same result as Zimmerman's lawyers. In my opinion, given the national coverage this case got, if the Florida public defender's office assigned to the case was anything like the ones in the jurisdictions I've experienced, Zimmerman would have likely gotten assigned two of the more seasoned trial attorneys in the office. Accordingly, I'd predict that they would be just as good as Zimmerman's hired private counsel.