I have used it a few times on customer cars at work, with good results.
Used it on triumph's and jaguars, a problem with the jag was that in the summer the normal coolant was always running out of the overflow pipe, now with evans it does not have this problem anymore.
The only reason i would not use Evans is because it's expensive, you need to buy the coolant and prep fluid.
You can use the prep fluid twice, so don't trow away after the first time use.
If you are planning to have the car for a long time, then i think it's a good investment, you never have to change your coolant again, unlike the normal coolant which you have to replace every 2 years.