While most lawyers will probably be able to help you better than if you were to represent yourself, all lawyers are not the same. If a lawyer handles many dwi cases, that lawyer can probably best help you. I have more dwi trials in a year than most New Hampshire lawyers do in their career. In a recent example, I was able to get a much better plea offer than the client got from his first lawyer.
Client was charged with second offense dwi and gave a breath test of .16. Because his first dwi was within two years, if he was found guilty, it would be a minimum 30 days in jail, plus the 7 day alcohol program. His first offer got him a plea offer to those "minimums". Client was not able to do 30 days in jail as it would cost him his job. He hired me for a better outcome.
At the pretrial the prosecutor first made the same offer. After figuring out the main goals of what the prosecutor wanted, I was able to propose a plea to dismiss the second offense for a plea to aggravated DWI. It had the minimum 3 days in jail imposed, with some suspended time hanging over his head. Additionally, we were able to get the client sentenced in accordance with the upcoming 2013 laws so that he did not have to to the 7 day inpatient program (he will instead do the IDCMP).
I have had many cases with this prosecutor, and he knows I am willing to go to trial. He also congratulated me on a not guilty verdict I got in a DWI case the week prior.
Different lawyers will not always be able to get different plea offers. However, if pleas fall through and the case is going to go to trial, your best defense is likely with a lawyer who handles, and wins, numerous DWI cases. I have helped hundreds of clients who have been charged with DWI and I am willing to fight to protect their rights and obtain the best result possible.