My brother and I have been using the Energy series since the last 3 years and we find it excellent.
I use the 205-65-15, whereas on his W123 he uses the 195-65-15. What I find most impressive of the Energy series is the fact that the tyres are very durable when properly inflated and aligned. On the W126, it lasted me 18 months. On the W123, it was almost 4 years! Then again, the W126 is a workhorse that runs 5,000 km a month on average, give and take 10% either way.
Do check out the tires catalog in
www.michelin.com and see for yourself.