I've found over the years that a top quality regular coolant mixed at 50/50 with distilled water and a nice flushed out, clean cooling system has always been fine. These are 1000cc engines...they run hot. My Blackbird has run up well over 100 degs on a hot day while moving and its fine. Mr Honda knew what he was doing when he built these things. They rely on air flow to cool we all know that. I've never boiled any of my bikes using top quality coolant and making sure the system is clean and working to it's potential. Just a thought. I personally wouldn't waste the money . Living in Australia we get some intense heat here in our summers and I've never had any over heating problems. I wouldn't waste the extra money on it myself. Cheers.