Imagine a date with a nice, cute girl who is easy-going, and makes you fell comfortable from the very first moment. And this date is getting even beter as the situation gets wet...
Okay, let's get a bit more scientific. If you're switching from a high-rolling-resistance tyre, the first thing you'll notice is how easy the car rolls on these Goodyears. Because of the hectic trips I've done on these I can't really tell how much fuel you can save, but I experienced a side effect of low rolling resistance: if you lift the throttle, the car won't slow as much as it used to, so brake wear will be higher as you have to use it more. It can be a bit annoying in town, but after you got accustomed to this, you will be able to think ahead.
And there are more good news: the grip limits are very high. You can throw the car into a corner at any reasonable (and even a bit more than reasonable) speeds whitout saying a little prayer before, and you will come out on the other end in one piece. And it applies to wet conditions too. These tyres grip like hell in rainy conditions. Considering that these are eco tyres, I believe miracles have happened when they designed them.
Other reviewers mentioned how comfortable these tyres are, and I strongly agree with them. The soft sidewalls do the trick well and make the ride very smooth which is useful if there are bad roads in your country. If you really like a plush ride, put them on a Citroën with hydropneumatic suspension (that's something I really would like to try).
Any drawbacks? Well, since nothing is perfect, there must be something. And there is. Because of the soft structure the road feedback is gone almost completely of the already not-so-communicative Astra. I wouldn't put these on a driver's car (by which I mean nothing more than a Ford Focus in this review). They soak up pretty much everything coming from the road, which is not always bad, but most of the time I miss the lost information.
A few reviews earlier someone with the same car with same tyre size said these tyres are good in terms of progressiveness, but I disagree. I believe the Firestone F700s I had earlier are better in this area (read my review if you want to). Even the 185/65 Dunlop Winter Response 2s (my winter set, you can read my review of them too) are better. Without the feedback I can't really feel when they are gone. Luckily the grip keeps you out of trouble, but if you want to find the limits, get your reflexes ready to get everything sorted again because it won't warn you when it gets too much.
Conclusion: if you want a tyre which has low rolling resistance, grippy and comfy, look no further, this is the perfect choice. But if you aren't looking for the travelling pleasure, but the driving pleasure, forget the EfficientGrip Performance. Would I buy them again? Well, I believe they suit the car well, and Rational Me loves them, but Petrolhead Me wants to get rid of them. To make peace, I'd chose the ContiEcoContact 5, and Dunlop's SP Sport BluResponse seems to be a good option as well, but I won't throw this set away. Instead I'll try to enjoy the benefits. And no, I didn't regret buying them, so they will go with the car (if they last long enough).