My wife and 10 year old son joined me for 2 nights of safari in February 2014. There is much to praise about Sanbona. The star of the show here is the Karoo - a glorious yet neglected part of South Africa with a terrain unlike any I've seen. Very dry and sandy soil but with a range of succulents and plants each seemingly in a different shade of green that produce a mosaic like beauty. The Sanbona folks excel service wise - our guide (Anthea) was a fountain of knowledge and worked extremely well with my 10 year old son. In fact, the Gondwana lodge seems to pride themselves on their work with children (especially younger ones) and we saw a lot of other families. The food was also tasty, particularly given the relatively isolated location. The rooms were spacious and stylish with nice appointments and views.
One thing to keep in mind though, particularly if you have spent time in Kruger or other wildlife reseves and that is that the game density at Sanbona is relatively thin and there is much less of an approach here on spotting the "big 5" as opposed to learning about the other supposedly less glamorous flora and fauna. The plus is that the isolation affords greater solitude meaning that you are never clashing with other cars or vehicles which can also be a problem at other larger reserves. All in all, Sanbona is a special place but if you're deadset on seeing big game close up you should probably look elsewhere.