The only text in Islam that is 100% infallible is the Qur'an. Everything else is up for questioning.
There are different levels of authenticity of Hadiths. Basically, if a person says "Prophet Muhammad said this..." then the chain of narration is examined to make sure that the line is credible. If there is questioning, the hadith loses authenticity. Therefore, there are hadiths that are considered "strong" (Bukhari, Muslim, etc.) which we can assume are credible quotes from the Prophet, and there are hadiths that are "weak" that we can approach with caution.
The Bible, for a Muslim, is not infallible since it has undergone too many translation processes, too much adding, deleting, re-wording, etc. and is considered "tainted" in that respect. The Qur'an is the only text that a Muslim can trust 100%. Hadiths, no. Bible, no. I would say, in my opinon, that a credible hadith is worth more to a Muslim than the OT and Gospel because a credible hadith is trusted as real words from the Prophet. The Bible is not. The Bible, since the chain of narration and editing was done by questionable individuals (scholars, rulers, authors, etc.) it would, if it was a hadith, probably not be considered "strong."
Hope it helps