Finally worn down the old Goodyear EfficientGrip Performance and got a set of these on Jonathan's recommendation. Pretty cheap too - Managed to get them for £55 each from F1 Autocentres online, including fitting, new valves, old tires disposed of etc. when the prices were fluctuating every day. Bargain! Esp. for these rims! Alas they've gone back up, stabilizing in the low 60's at time of writing so I lucked out there!
Initial differences - The road noise is slightly but noticeably better; It's still pretty loud on certain surfaces but not as obnoxiously loud as the Goodyear EfficientGrip Performance were, esp. on concrete slab sections of motorway where the EfficientGrips would leave me with tinnitus because they were so f'ing noisy! Again shows that the official tire noise rating is useless as the EfficientGrip Performance is rated at 67dB vs the VentusPrime's 71dB so it shouldn't be quieter!!
Grip is noticeably better over the EfficientGrip Performance, at least in the dry - I've yet to trigger the ABS under heavy braking, and it gives confidence that when I want the car to stop, it actually will stop! This was a constant issue with the Goodyears - Under anything other than a perfectly dry flat smooth road, would often suddenly run out of grip when braking hard, triggering the ABS and costing me 50% of forward braking force making the car feel like it was suddenly lurching forward!
Also, there is a fairly steep right turn I often need to take at junction that has poor visibility and is onto a fast road so I want to clear the junction and get up to speed quickly - I find this is a good test of a tire's grip as it has to contend with sudden high acceleration force and still deliver lateral grip; In my crappy FWD Yaris it's quite a good torture test of a tire's grip.
The EfficientGrip Performance would almost always wheelspin if I just floored it, losing me forward acceleration and forcing me to back off until I'd straightened the wheel, leaving my rear hanging out longer than I'd like.
The VentusPrime3 has been much better - Several times now I've been through that junction and accelerated at full power into the turn and so far I've never spun the wheels up at all, it just hauled off like I expect them to. Feels much safer and gives me more confidence than the Goodyears did!
They do seem to ride a bit harder than the Goodyears, although this is at the higher PSI I tend to run my tires at - At stock recommended PSI they absorb speed bump impacts and drains etc. as well as most tires. The difference in shock absorption between low and high PSI is more noticeable with these than the Goodyears. Might be a factor of sidewall stiffness?
Very happy with them so far - Hankook have made a very good tire here; My only concern is how long they will last, and how much the performance will degrade over its lifetime - Last time I had tires with such good initial impressions was with the Continental Premium Contact 5 - I gave them high marks across the board initially, but quickly discovered the horrific wear rate. I think they lasted half as long as tires normally lasted on that car and that totally negated the relatively low cost (for a Conti!) of it.
(Supposedly they have fixed this in newer version of the CPC5 but the price has gone up by over £30 since then too!)
Hopefully that won't be the case with the Ventus Prime 3 - We shall see when I've put some real miles on them and they've been through all 4 seasons!