The traverse of the Sierra Nevada is a superb trip to do. It offers great hiking, many beautiful sights and scenes, and a very special experience of the conditions and culture of the Sierra Nevada. The proposed 5 day trip can only be accomplished (by normal mortals) if previously acclimatised. Otherwise I'd plan 6 or maybe 7 days. Doing it from East to West (as per most propositions) might be more efficient as from West to East. Clearly I would recommend the traverse to anyone.
I thoroughly enjoyed Javier as guide. He is knowledgeable and experienced in the Sierra Nevada, has a very pleasant and helpful disposition, and is cautious yet adventurous. He creates an atmosphere in which one wants to explore/hike. Javier knows what he knows and is confident, and he is open to new ideas and other experiences. That requires natural self-confidence, which he has. I would recommend Javier to anyone as a guide.
The services and network of SpanishHighs are more than sufficient to have a great experience. I would recommend SpanishHighs without hesitation.