Today I finally had a chance to go for a (long and varied) drive to try out the Kirkosaurus urethane torque mount inserts. I love them!
 
If you don't know what they are, the Kirkosaurus "motor mount inserts" are pieces of moulded urethane which you push into both sides of the standard front and rear torque mounts. They fill in the voids around the rubber in the standard mounts, and firm up the mounts in general. Note that the left and right engine mounts remain unchanged, as they only hold the weight of the engine.
 
There's a subtle change in vibration through the chassis, particularly at idle as expected, but I don't find it annoying. If anything it makes me feel more connected with the car and the engine, in a good way. Some people may react more negatively though, especially in cars with less modifications.
 
The added firmness of the torque mounts has significantly improved the feel of the car in many ways, such as:
 
- When pulling away normally from traffic lights, it is much easier to pull away smoothly because the engine doesn't rock back and forth so much. Previously if I did a not-so-smooth take off, I always assumed that it was caused by me and the clutch, but in fact it was the torque mounts all along.
 
- If a gear change isn't quite perfect, I was expecting it to feel worse and more harsh due to the harder torque mount inserts, but I was pleasantly surprised to find that every gear change actually feels better now, because the engine isn't moving so much.
 
- When approaching the exit of a corner and getting back on the throttle, the entire car feels a little more stable because there is less weight transfer of the engine in the torque mounts.
 
- Of course there is also the benefit of improved throttle response. This is the main thing that people advertise and talk about, but I actually noticed all of the above improvements before I noticed this.
 
I had no idea just how much my worn torque mounts were having a negative effect on the feel of the car in so many ways! There were many things that I assumed were normal until I installed the urethane torque mount inserts. It's hard to say whether my standard engine mounts were worse than average or normal for their age (when not using all of the torque that my car has compared to stock). Upon visual inspection of my standard torque mounts, the rubber was still intact and attached at all corners, with some cracks which I never would've expected to allow as much movement as they did.