In general you will be either a 0/10, 5/10 or 10/10 match with with your siblings and probabilities are 25%, 50% or 25%.
If you google haploid SCT you get a lot of hits for example:
http://www.ncbi.nlm.nih.gov/pubmed/16965686
Haploid HLA-matched allo-HSCT is a relatively efficient method for the treatment of patients with malignant hematological disease, who have no related matched donors. Nevertheless, strict administration should be carried out since it's a high risk approach.
Personally I think I would prefer an good unrelated 10/10 but listen to your doctors.
Keep in mind that either rejection or GVHD can kill you. I am having some GVHD and the doctor said with too much immuno we kill you with rejection and too little we kill you with GVHD. It is a fine line in between and we really don't know where that line is. No regrets on the SCT.
Ray