Complex sentence: The "Hunter boxes" apparently proved popular with U.S. troops, but were criticized by senior officers for their lack of overhead protection, and for being top-heavy, however few cases exist to prove their doubts in this equipment.
Split into simpler sentences: The "Hunter boxes" apparently proved popular with U.S. troops, but were criticized by senior officers for their lack of overhead protection, and for being top-heavy. However, few cases exist to prove their doubts in this equipment.