We absolutely loved our stay at Siana Springs, Intrepids. The staff are all very helpful and efficient. When they ask about how your safari was, they truly are interested in hearing your answer, its not just a rhetorical question.
Although, the accomodation is tented, you do not want for anything. There is a WC cubicle and a shower cubicle with running hot water. We did not have any creepy crawlies inside the tent. And as long as you are conscientious about keeping the tent zipped, you will not have a problem with flying insects either.
Since they generate their own electricity, power is on for a few hours in the morning and in the evening (when you need to be awake and there isn't enough natural light) These hours were enough for us to keep our 3 cameras, 3 cell phones and 1 laptop charged daily (2 plug points in the double room)
Tents cannot be locked, so if you are carrying valuables and want to be carfeul, carry locks for your suitcases, but the place seemed very secure.
Every morning and evening, we relaxed outside our tent watching the bush deer which came right up to the tents, the vervet monkeys, who wait for an opportunity to pounce on the food of an unsuspecting victim, or to get into your tent to search for goodies, the hyrax - which is a cute tiny animal who makes the loudest sound in the middle of the night and the family of 10 Columbus monkeys on the grounds.
The food here was tastier than our other hotels in Kenya on this trip. The packed lunch on our whole day game drive was simple, but tasty. Prices for additional beverages are reasonable. I think it was around 100Kshg for a 1 liter bottle of water. Complimentary tea, coffee and hot chocolate are available throughout the day.
I'd highly recommend the Cultural talk given by the Masai every afternoon between 2:15 and 3:15pm. The masai conducting the talk speak fluent English and can really answer any questions you may have. They have an adventurers club for kids which most of the kids around seemed really happy with. This was the only place, we saw on this trip that made an extra effort to keep kids productively and interestingly occupied.
There is a massage room on site, in case the road is too bumpy and you need to ease your pains gently. Didn't try it so can't comment on how good it is.
The hot water bottles in our bed were an absolutely wonderful and extremely welcome touch at the end of the day.
The only downside is that it is a half an hour drive away from the Masai Mara reserve gate. So if you plan to do 2 game drives (morning, evening) in a day, then you spend 2 hours on a very bumpy road viewing mostly cows and goats.