This is relating to the product for the 07-12 JK's, not the same named product for the TJ's or YJ's.
Well, these things are a mess. They mount directly over the top of the hood hinges, the bolt holes line up well, and they do hold a jack securely. Unfortunately, what they don't do is allow you to use your windshield sprayer. The jack can only be mounted one way (with the handle towards the windshield). If you mount the jack the other way the "toe" of the jack will dent your cowl (no, I didn't do this...I saw that it was likely and checked while very carefully lifting the hood).
Even mounted with the handle away from your windshield (which wouldn't allow you to open your hood all the way) the jack would block about 90% of your windshield spray. Mounted the correct way (with the handle towards the windshield) blocks 100% of the spray.
I would have assumed that someone would have tested this on a Jeep at the manufacturer before deciding to sell the product. Honestly, as soon as I mounted the jack to it, it was the first thing I noticed and decided to test.
Simple answer: Do NOT buy this product unless you intend to relocate your windshield sprayer to somewhere closer up to the windshield (definitely not worth that level of effort IMHO).
-10 rating overall in my book.