I would recommend fitting them.
I have the ECS one on my manual non Ed30 GTI with a remap.
The engine movement is reduced quite a bit, you haven't got that feeling of a large lump of metal bucking up and down in the car.
Shifts seem to be a bit smoother as well, and easier to make. Before with spirited driving I noticed I had to be quite precise when shifting. Most noticable for me the 2 - 3 upshift at high revs, just couldn't find 3 quickly and smoothy, not so anymore after the dogbone.
Pick-up of the car is also improved, you haven't got the feeling of the engine 'settlling itself in its mounts' before delivering power to the wheels.
On the negative side, I feel a bit more vibrations through the throttle pedal compared to before, and that is actually the only place I feel it continuously. I don't find that an big irritation or something to put me off, but that can be differen for each individual.
Furthermore you get a bit more vibrations if you balance the car on the clutch biting point with the engine at idle revs. A little revs cures that.
All in all I would recommend it, a great modification for little money.
Install was done (for free!

) during a GTI meet at a local dealership. I would suggest you put the car on a bridge to do the install, it is a tight fit and you need some working room under the car to give it some leverage.