Both Dahab and Nuweiba are growing but remains less developed than Sharm El-Sheikh.
Sharm El-Sheikh is not quite as developed as either Nuweiba or Dahab.  
mnli hypothesis: Sharm El-Sheikh is not quite as developed as either Nuweiba or Dahab.   premise: Both Dahab and Nuweiba are growing but remains less developed than Sharm El-Sheikh.