We have splitted our holiday between River Lodge and Duline after having seen this thread. We have came across a lot of people who were also in doubt.
There are a lot of similarities and also several differences between the two camps.
There are 6 lodges in Dulini, compared to 8 in River Lodge. In both camps there are two vehicles. In Dulini you will therefore pretty much always have a maximum of 6 people in the vehicle (two per row), while this can be a larger number in River Lodge.
Dulini feels like every lodge itself is located right in the bushes. Niala (impala's) are almost always present in the camp. At night also other animals (apart from elephants) will cross the camp. From the lodges at Dulini you can see a river, which was pretty much dried up at the moment we were there. River Lodge feels more like you are on a platform, overlooking the (big) river. Although animals (including lions etcetera) walk through the camp, you get less of the feeling you are in the middle of the bush. The first day we sas >35 elephants from our lodge, later on we saw a hippo and 2 giraffes.
The atmosphere is also different. In Dulini it is more personnal and warmer, although this is relative and the staff in River Lodge was also great. The difference lies in small things: when we arrived at Dulini we were welcomed by loads of staff, which gives this extra something.
The guides and trackers we had in both camps (Steve and Jack/Isaac and William) were very experienced, service minded and knowledgeable. The butlers we had (Reply/Christopher) were also great and very interested in all our stories (which they must have heard a lot of times).
If you are a birdy, we can certainly advise to arrange a private vehicle with William at River Lodge to get the maximum out or your stay and to prevent any annoyance with non birdy's (the great majority of the people - who come to see the big 5).
The lodge in Dulini was twice the size a the lodge in River Lodge. However, both had a bath, a plunge pool, a sitting area etcetera. The Dulini lodge appeared more 19th century colony era, River Lodge oozed the vibe of a modern lodge trying to replicate that atmosphere.
It is really hard to advise on or the other, and really depends on your preferences. It was very nice to have the opportunity to experience both.
Both lodges are not cheap, but bear in mind that you will get two game drives a day, three great meals (a two course breakfast, three course lunch and three course diner/bush diner/festive diner), open (mini)bar, snacks all the time, with top notch guides and rangers (who had lengthy courses from And Beyond and are selected on both their knowledge and soft skills), by a non-profit company that is very thoughtfull and respectfull about their impact on the wildlife, perfect service, very nice places to stay. Furthermore And Beyond invests a lot of money in housing and schools from local people. The rangers/guides have continously contact with the other rangers/guides in the area to ensure you get to see what you want. We saw the big 5 (white not black rhino though) within 24 hours and saw so much activity.
We booked our trip (including return flight) through Wildlife Africa Safaris (Ernest was our contact) who gave us a good deal, was very patient (despite our indecisiveness and enourmous amount of questions) and gave us so much information on these two lodges. We would definitely recommend him.
Edited: 7:34 am, December 06, 2012