Well-organized, accommodating, friendly, and experienced guide service. My friend and I did the two-day Mulhacen winter trip. Were lucky to have cooperative weather and a successful ascent with great views but even if we hadn't I still would have felt that the trip was well worth it. Our guide was familiar with several routes and involved us in deciding which option would be best for us.
There was enough time allotted in the schedule to allow for flexibility with our pace when one of us was coping with a stomach bug (whose origin was unrelated to this trip). Despite extreme familiarity with the mountain, our guide never seemed bored (in fact his summit photo looks much more triumphant than my own). Instead, his extensive experience was channeled into teaching us about the location and his apparent enjoyment of the trip added to our own.
Based on this experience, I would definitely feel comfortable planning another trip with Spanish Highs and I would recommend them to anyone seeking some memorably enjoyable and safe mountain time.