Recently returned from a stay at the Mara Siria. I like quiet small places and sought this out after realising that so many lodges and camps on the Mara catered for very large numbers of people whilst this only had a dozen tents/rooms. It turned out to be perfect for me - quiet, great atmosphere and wonderful views of the Mara. The tents are excellent - simple but beautiful and roomy; well spaced so you feel on your own at your tent.
Staff were excellent - Joel and his team provided good quitely efficient camp management, Moses was a font of knowledge both on local customs and the flora around the camp. Frances our driver enhanced my personal experience with his knowledge of bird life.
I really liked the atmosphere and despite others comments I did find that I could wander around on my own with my binoculars, although for longer walks they did insist that you take a member of staff with you.
The only drawback for me was that despite being off season there was a fair number of vehicles in the reserve. I think that this is a result of Kenya's success with tourism and particularly the Mara, and there are many camps and lodges around this part of the Mara. However we did see an amazing amount of wildlife. Seeing the wildebeest migration I am sure is spectacular but for me it was good to be there off season and relatively quieter.