We just had an excellent stay at Singita Sweni in late August. understand that both Lebombo and Sweni were just renovated (or in process). Overall an excellent stay especially when you combine the trip with Ebony or Boulders. Sweni is much smaller than Lebombo and quite intimate. The guides and grounds for both lodges are the same. The decor and size of the lodges are what differ. I recommend Singita whole heartedly, so much so that we are staying at two Tanzania lodges in May. Please let me know if you have any specific questions.
Also, have you done a search? There should be lots of info in the luxury hotel forum.