Had you been successful at a suppression hearing, you may have obtained a better results, but keep in mind that 1) suppression is extremely rare, and 2) your attorney was likely in the best position to anticipate which way Judge Gruber or Judge Cavarello would lean at the hearing.
Had the case went forward to trial, your BAC was presumptive evidence that you were intoxicated, and you would have been facing a misdemeanor conviction and far more significant penalties. See the attached link to the jury instructions.
You are very fortunate to receive the offer to a DWAI. In many counties, outside of Erie County, there would be no negotiation on a second charge if there had been a previous reduction. It is not common in Erie, either, so appreciate the opportunity that was given to you and don't second guess the decision that you made.
Also, keep in mind that a third DWAI is a misdemeanor according to the Vehicle and Traffic Law. If you have a drink (even just one), I would suggest not getting behind the wheel. A cab will be cheaper than a lawyer if you are pulled over for any reason.
You made the safe move. You avoided a criminal record.
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Why are you now second guessing what you did? You did well, but that is not the point, unless your case was not prosecutable for some obvious reason. I am sure you and your attorney discussed things in detail and you felt this was the best option. Let historians worry about the past.
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