Having used Kumho winter tyres with good experience, I confidently changed to PS71.
Initial reaction was not as noisy as the old Dunlops, but there is a distinct feeling that the tyres are soft which prompted me to immediately think the fitting station had got it wrong; but the pressures were spot on.
By 700 km from the south coast, via Calais down to Strasbourg the Hybrid "Economy Meter" had climbed from 4.8 lt per 100km to 5.5lt per 100km.
I have now done 1400km and the Economy Meter has stayed at 5.5lt.
Very disapointed, but next month I have to put on the winter tyres. (by law)
My choice but sorry Kumho !

I did some 17.000 km on these tires. The grip is still on the same level, no matter the road, dry or wet. Slowly showing some signs of ware, but still pretty much all of the profile available still - the "checkered" flag marking disappeared on fronts, still some visible on the rears.
Had some problems with vibrations, but after rebalancing these tires are really comfortable. They are a bit louder than when they were new, especially during city braking.
They are not as "eco" as the Michelin Primacy HP I had before, maybe about 0,3-0,5 l/100 km of fuel consumption more, but on the other hand the car really drives nice and also give more information about what is going on under the tires.
Definitely the Kumho Ecsta PS71 are on par with the premium tires (at least comparing to Michelins which were fitted prior), but for a fraction of the price.

Had these tyres fitted to front no problems very good tyres hold road well very good in wet conditions,they seem to need a but more air pressure then 32psl so increased to 36psi have kumhos ku 39 sports on rear also good tyres.

And the same Kumho problems with Me.. balancing & egg shape. 215/45/17 91Y XL
I've often used Kumho Ecsta PS31 ,because have a chance to do it and they didn't need constant rebalencing.
These Kumho Ecsta PS71 are something different.
You will get "massage" , "constant lane change warning function" and sunshade vibrations for free.
Avoid buying them!

In the end, I decided to go with Kumho's, because the dealer said these tires are really good, even though they are much cheaper then the rest of the tires (got them 70€/tire). At first, I must admit, I was a bit concerned. The grip was ... strange ... especially on wet roads. They were good on dry road, but in the wet, especially on the highway, I had no feeling, what is going on, it was almost like I was floating but there was no aquaplaning since the car was not sliding or losing grip. Really hard to explain. Then I checked different pressure values and found out that when inflated on 2.6 or higher, the tire becomes completely different. And the feel on the steering wheel, even on Prius, which has a very numb steering wheel feeling, became something completely different. Maybe tires needed more time to "run-in" than usual, but now, after cca. 3000 km on them, I am really satisfied.
I just returned from a trip to Tuscany, after some 1500 km on the typical windy roads, there was no problem. Even with some spirited driving, grip was great, feel was great. Yes, Prius really is not a car that "likes" windy country roads, it is great in city, great on highways, well with these tires, it does not oversteer so much any more and it is fun to drive also on country roads.
A part of the return trip from Tuscany also included driving on really wet roads and the feeling was there, no aquaplaning even on harder breaking. I guess these tires just need a bit more time to run in and a bit higher inflation pressure.

same kumho problem... balancing & egg shape. 245/45/18 100Y XL
I've always used kumho because the price well reflects in proformance if only they didn't need constant rebalencing.
I've had 4 duff pairs, ku31 x 2 pair, ku 39 x 2 pair that had to come off in the end they were so bad.
No amount of balencing can sort an egg shape tyre.
These new ps71 are very soft, squishy, feel like running on 20psi with 30g wheel wobble even after twice rebalencing them & 1 of them is egg shape.
I am worn out with trying to get them right & think after years of kumho on various different cars I'm giving up on them.
Changing to Dunlop.
I always feel bad going back to the shop to moan they must think it's me lol but kumho have let themselves down & I will say so.
PS71 is more expensive, lower spec & lower quality, not for me, I like a tyre to be not thought about coz it's getting on with it's job instead of feeling there's a 60mph side wind blowing me around & the steering wheel hammering out of ny hands not to mention the amount spent on rebalencing & hanging around tyre shop waiting for my turn.