This has the most stunning session and is really a totally lovely place. You need to be keen on the idea of ayurveda as the entire spa is run on its principles. Generally you see an ayurvedic doctor and your treatment plan comes out of that (although you can add on beauty treatments which are excellent).
The food is beyond fabulous - generally three or more courses but so perfectly balanced that you don't put on weight. You can even do a workshop with the chef to learn how to cook ayurveda-style at home.
Yoga is obviously a strong part of the ethos and classes are good (though not all teachers spoke English and so you might be a little limited in your choice of class if you're new and need instruction).
The pool is beautiful, so serene and the surroundings are stunning too. It's set amongst vineyards and you can walk up fromthe hotel through these or down into town and along the river - there is even a small icon museum in town.
Be warned. As you detox (no coffee or alcohol) you may get a stinking headache (but the staff will take pity and give you something for it if it gets really bad).
The massage treatments are fabulous - many are given 'four=handed'. Be aware that you will usually strip right off for these as a lot of oil is involved. Germans don't hold with undue modesty so you just get on with it! Therapists are lovely and you feel seriously cocooned and cossetted (but these aren't purely fancy 'rituals' - they have profound results).
Lectures and workshops are also included so you learn the theory behind ayurveda.
Just lovely....writing about it makes me feel a serious yearning to go again!

Nearly forgot. Downsides? Not many really. I did find the decor less inspiring than I'd hope, both in bedrooms and in downstairs areas such as lobby, restaurant etc.