Not all naturalization cases are easy. The easy ones are those in which the applicant can easily establish five years of good moral character prior to filing. But some people have a less than perfect record. Once the entire record is obtained and reviewed by the attorney, the attorney can tell you whether to take a risk and apply, or whether to not apply at all.
Anybody with an aggravated felony received after the passage of the 1990 Immigration Act will probably find it a waste of their filing fee to submit an application for naturalization. Also at risk are people who obtained their immigrant visa and did not report their criminal history. If the criminal history is a conviction that would have barred them from obtaining the visa, the filing of the naturalization application will expose their case to the immigration authorities. If there is any problem with the marriage on which the petition to obtain the green card was based that might make it look like there was marriage fraud, filing the naturalization application will put the applicant at risk.
It is very important to be totally honest with your attorney. The attorney can weigh whether or not you should not proceed and whether it is worth the risk. It may be worth the risk if the criminal conviction is very old and the applicant has turned his or her life around and now has many positive factors to show. In this case, the good factors will outweigh the bad. A good attorney will organize your case to make your good factors stand out.
If you have a less than perfect record and you want to become a US citizen, it is worth consulting a good attorney.