Thanks for helpful response - seen a few of your threads on spark plugs(!) - am pretty sensitive (and a delicate flower.... ;-) ) - have a few track cars and do feel the difference between components (new coil packs make a difference, worn bushes etc) - but never had a car with this type of mileage "from-the-off" - where any "deterioration" would have been very gradual - and having done maybe £300 miles in the car - it feels good - but not sure "how" good it was supposed to be.

OCD will prevail I think. Will run through the car over a couple of weekends.

Thanks for responses.