We are a family of four with kids of ages 8 and 11 staying at the Yaiza for a two week vacation (Aug 06 to 19, 2014, so still there at the time of writing). The question we had when we booked our vacation package in such a luxurious hotel was - is it worth the cost. I am guessing that many families checking out tripadvisor will be asking themselves the same question.
On the plus side, facilities and rooms are outstanding. Yes, they are twice the cost of a four star hotel, but what you get is twice as good, or better. Our family room has two big bedrooms, two bathrooms, a living room, a nice terrace and plenty of amenities (two TVs, microwave, a real fridge). Hotel facilities like the gym, pools and common areas are truly amazing. There are large areas dedicated to children and families, which is good in my opinion for both families and non-families. Also a plus is that the estate is very large so you don't experience crowds. And the staff is extremely nice and attentive to detail. The maid, for example, began to add an extra blanket to the bed of one of my daughters - without us saying anything - when the kid took the extra blanket from the cupboard two nights in a row.
Unfortunately what could have been a perfect stay is turning out to be a mixed bag of experiences because of the meals. Half board, which is usually a winning strategy for families gives you access to the Hotel buffets, which are all of them great.
But half board is expensive - quite expensive as it turns out: dinner is 112€ for 2 adults and 2 kids, that's 150$ a night folks, drinks not included - and that's at the special discounted rate they offer at the lobby. That may be an acceptable tag for that "special" night, but if you like dining lean it does not make much sense to pay 30€ (~40$) a piece for a salad or a slice of fish, specially in the context of a long two-week stay like ours.
That being said, if you are comfortable with that level of spending, then read no further, this is the perfect place for you, you will not regret it.
But if that is not the case, I am dismayed to say that there is really no easy alternative to the half board. The hotel does have several other restaurants but none of them seem to fit the casual, unpretentious, family oriented profile that we favor. For example, we tried the Don Giovanni (italian) but we had a disappointing experience at 70€ (one dish per person, no wine, no desserts), involving a rather small portion of salmon which left my 5-foot wife hungry.
Let me add that this is the only Hotel where I have been in the whole of my life where I found that ordering room service is a more sensible option than actually walking down to the restaurant.
There are many restaurants at walking distance around the Hotel and those are a good alternative. But it is certainly a let down that we have not been able to find a solution to our meals within Hotel grounds.
