It does have a ceiling effect, which means someone can only you can't get high the more you take it. However, this doesn't stop you from overdosing if you keep using other drugs with it to get that high feeling.
Yeah, subutex does have a ceiling effect but this doesn't always stop people from going overboard and mixing it with another drug to get high. This can be bad as well since you could overdose more easily by combining the two.
Subutex does have a ceiling effect, which is good since it's supposed to help people recover from their addiction. However, this doesn't stop other people from taking another drug with it to get that high feeling with means the ceiling effect won't work anymore.