An ST is on my list of cars to purchase next, how do you find it day to day? How is the refinement, power delivery and comfort?
Day to day its fine, plenty of torque makes town driving a doddle, 20mph in 4th is not a problem. It's just subdued enough at low revs to be driven around town easily. Motor ways are just as effortless - again, the torque means you put it in 6th and leave it there.
Refinement in general is fairly good, most STs suffer from rattles though, although fstoc has guides to solve just about every one you'll ever find (I've been lucky though).
Power delivery standard is slightly reminiscent of my old Corrado VR6, under 3.5-4k RPM there isn't a lot there, which makes driving around normally really easy, in fact, I've almost found it encourages me too, unlike some of my previous cars that didn't feel right when driven sensibly.
Remapped it becomes a different car - you still get that low down "easy" spot, but you get a huge torque surge at around 3k RPM, ie. put you in the back of your seat surge, and will generally pull hard to around 6.5K RPM in first, second and third. In the higher gears, that low down boost peak causes boost to drop off higher in the rev range with the longer gearing, although, it tails off to around 0.7bar which is still better than the standard boost, so you're not losing anything.
In terms of handling and grip, it is mostly point and shoot - the car does pretty much what you tell it to, other than the odd inside wheel spin-up if you jump on the power a little too early out of a bend. I haven't found understeer in my ST yet, it appears to be more biased towards a little bit of oversteer, but then I'm generally quite good at finding a cars limits, so really pushed past its limits, I couldn't comment.
With regards to the above, with the Traction Control/ESP switched on, you can get away with a lot and it does a bloody good job of keeping you pointing in the right direction, without being too interfering. Its even saved my ass a couple of times when I've been driving along sensibly.
Comfort is brilliant for what the car is to be honest. I mean, its no 7 series, but it soaks up the bumps with little effort and without being crashy, and the leather seats are sublime - even on long journeys, I never feel the effects of the long drive like I did in my old VXR. Its also worth mentioning, I've yet to have it bottom out, and I believe it is the first car I've ever owned that I haven't managed this on over our terrible roads here.