While I've never had a DUI before I've had several other driving problems end up and court and always went to them with no legal assistance and seems to me no different to those with some type of legal assistance. But, the one time I did have a Public Defender for an incident that was not traffic violation the Public Defender seemed as knowledgeable as any other lawyer and was very helpful to my case, so in my experience a Public Defender can be a good thing and better than being not represented in some situations. So if you can't hire a regular lawyer I'd stick with the Public Defender. But this is just my opinion.
Wes