Inflating tires to 51 psi

Has anyone tried running their Prius at something around 50psi?

I saw three tires in the OEM 185/65r15 size that take up to 51 psi and was wondering if anyone has tried any of them, especially on the Prius, at high inflation, or with an eye to mileage or fuel efficiency.

Continental ContiProContact
This is the replacement to the discontinued low rolling resistance CH95 EcoPlus. I don't have any data on the rolling resistance of the new ContiProContact, but all sizes now inflate up to 51 psi, while only select sizes and BMW versions of the CH95 inflated to 51psi. These tires come on Audis, BMWs, Jaguars, etc. These grand touring tires compete with the Michelin Energy MXV4 Plus, yet they cost much less ($72) and are better rated by tirerack.com customers.

Falken Ziex ZE-512
When Consumer Reports tested performance tires a couple years ago, they ranked these tires #1 overall. That was before considering price. At $48 each shipped (from discounttiredirect.com), they are extremely affordable. Consumer Reports also reported that they have low rolling resistance. We've driven these on our Civic and have been very happy with them. They have thin, fuel efficient sidewalls and do well at high inflation.

Sumitomo HTR H4
Though not as well known in the US, Sumitomo, headquartered in Japan, manufactures and markets automotive tires under the Dunlop, Falken, Goodyear, Sumitomo and Ohtsu brands. The HTR 200 is a favorite of performance enthusiasts looking for a low rolling resistance tire with outstanding traction and handling. The HTR 200 is a summer tire and available in 195/60-15 but not 185/65-15. The new HTR H4 is a new all season performance tire and is available in our OEM 185/65-15 size. These cost $56 shipped from tirerack.com.

Has anyone used any of these tires?

What pressures did you run them at? How was the rolling resistance and fuel consumption? How tolerable were they at high pressure?