There are a lot of views on Evans coolant on the web; do a search for reviews. Most of the 'for' views are not very scientific and largely are a justification for the high price of the stuff, and the rigmarole in getting the water out. In other words, I've spent a lot so it must be good. I did find a scientific 'against' view but it has to be said, the writer has an interest in more normal antifreeze.
It may be a good thing for a museum vehicle as there ought not be any corrosion, but I have my doubts for anything that is used, especially raced since the heat capacity of the coolant is reduced.
Not having had one, but I understand the +8 is often a bit marginal on the cooling front, and anything that reduces it, ie a coolant with less specific heat capacity, is not a good thing. Plenty of owners use 'water wetter' to effectively increase the specific heat capacity. Extension brackets for the rear bonnet catches to increase underbonnet airflow seem a cheap, easily fitted device and I've seen plenty of racers with them.
