I flew Business class LHR-MAD and back last month, and took the plunge by booking IB rather than the (to me) more familiar BA flights.

I have to say my experience was the complete opposite of OP’s except that my flights were also bang on time. The crew were kind and enthusiastic both ways. They were proud of the Spanish wines, and justly so since they were far better than anything I’ve encountered in BA Club Europe. The food was also much better, with a choice of two hot options that seemed more interesting than what I’d expect on BA. The armrests raised! The only downside was the Avios and Tier Points took over a week to post.

If/when I return to MAD I shall certainly choose IB over BA, assuming price, schedule etc. are much of a muchness.