Hi Debbie,
We have been using our Biolan Naturum for six months continuously and are very pleased with it. We bought it from Germany:
http://www.oeko-energie.de/produkte/komposttoiletten/index.html as it was 1,300 euros as opposed to the £2,000 for the same thing from the UK. It took about 4 weeks to arrive, but was very simple to buy and install and the owner of the supply company was very helpful. The only problem we had is that when we installed it we didn't vent it properly, meaning to come back and add the extra piece into the vent (it was only a drainpipe) but we got some insects before we got around to it. Once we vented it as per instructions, above the roof, the insects went and it was fine. It is easy to use, doesn't smell and only needs emptying once a month. We don't use special compost, just the local organic stuff with a few wood shavings. It is expensive, but it is our only toilet and as we are building a house as well as starting a garden from scratch, this has allowed us to save some time and hassles. I completely recommend it, worth every cent.
Good luck!
Yolanda