I've been. I took 2 small kids with me. We had a great time, stayed on a campsite in a bungalow which was clean and modern and fairly roomy. The lake is interesting - a bit green and slimy more for water sports than swimming I thought. Eating out is great, good food and wine and all just SO cheap. We hired a small car and drove up to Budapest for the day. This was a lovely city but needs much longer to be explored properly. There are loads of things to do, wineries to visit, tourist attractions, thermal lakes (bizarre), stunning forests, great walks, bike hire and some half decent shopping. It is an unusual place to visit, you really know you are abroad which I loved - the language is very different, we had great fun trying to learn it. If you like a bit of safe exploring, this is a great option, fly with Ryan Air and book directly with the campsites on the internet.