If you liked Alan Bennett's TV monologues ("Talking Heads") or his autobiographical essays ("Untold Stories"), you might as well get Smut straight away. It has the same incisive wit and observation and delightful turn of expression.
If you aren't familiar with his writing, it is intelligent, entertaining, and funny, but in a deadpan, wry style, not laugh-aloud. His dour Yorkshire accent is perfectly suited to the style. For that reason I would strongly recommend the audio version, and I wouldn't be surprised if there was no print version.
Be ready for some very explicit sex. If you are unsure whether it would offend you, I would suggest giving it a try. Although there are some graphic moments, it is extremely witty and - I hesitate before using the word "unique" but Alan Bennet finds a genuinely unique and delightful angle on the subject.