In reality, whether a DUI or a DWI is worse will depend on the state in which you live. In Texas, DWI is a more serious crime. DUIs are only charged to minors under the Texas Traffic Code. However, because you are accused of drunk driving when any amount of alcohol is found in your system, it is much easier to be found guilty.
In general, a DWI is worse, especially if it's a second or subsequent offense. You risk spending more time in jail or prison, higher fines, and having criminal records that cannot be erased. Fortunately, as for the collateral consequences of your drunk driving, drunk driving and criminal records, for first-time offenders, the law has recently changed and you may now be able to opt for the elimination of the death penalty. This means that once you have paid your alleged debt to society and successfully obtained an elimination of the conviction through the efforts of your lawyer, you will no longer have a criminal record after a criminal background check.
In addition, you will no longer have to disclose to a future employer that you have been convicted of a crime or disclose it to a bank when you apply for a loan or otherwise disclose it when you are asked to disclose the commission of a crime. DUI offenses are class C misdemeanors, while DWI offenses are actually class B misdemeanors. An exception for DWI offenses is if the person's BAC is recorded at 0.15 or higher. The case is then classified as a class A misdemeanor.
If a poisoning incident causes bodily injury to another person, then the particular crime could even be classified as a second or third degree felony. In Texas, felonies carry prison sentences ranging from two years to a full decade and fines of up to ten thousand dollars.