Flew UL to MLE, and was very happy. Better than EK, who I flew on the return journey.
CMB is pretty basic, but there are day use rooms available. You can have a sleep and a shower. I would go into town. I stayed at the Galle Face. Very stunning colonial style hotel overlooking the Indian Ocean. Massive rooms, but I can't remember the price.
Ask your travel agent about UL's STPC program. They often provide complimentary hotel accommodation if you have a long transit, but it depends on the fare and the length of time you are transiting for.