With my Wife's car, the throttle response was affected and as such so was the low revs. Meaning, you would often bog down on pull off unless you were revving the engine, but if for some reason something delayed you for a millisecond while doing this (car in front hesitating for instance) the engine revs would drop again and you end end up bogging down again! This also affected gear changes and of course this also made the engine prone to stall quite easily, especially when reversing in parking areas etc.
To be honest, I don't think that the seals on this car were even as bad as they could be compared to the extent of the typical symptoms, but with that said, there is a huge improvement. I drive the car very seldom, so for me the issues were always a problem and I would battle with the throttle response and bogging issue - performance was not "bad" even at lower revs, just the instances when you were pulling off or manoeuvring the vehicle in parking areas. But after the new seals were fitted, completely different and a pleasure to drive!
What confirmed this all for me was the fact that I had not told my Wife about what the expected improvements or the finer details of DIY etc, but when she took the car for the test drive (had her drive since she knows the car), I eventually asked her if she notices anything different. Immediately she said that she could feel that the throttle felt much better and that it pulled stronger at low revs. She even said that she has to now "unlearn her bad habits" because of the way the engine used to behave, and even when I drove it I could feel the difference and that how I would previously have driven the car to overcome these issues would then cause problems now. So really, it's like driving a different car! And definitely for the better!
