[thstone]

Depends on what level of NVH (noise, vibration, and harshness) you find acceptable.

When my stock engine mount failed, I installed a semi-solid or "performance" motor mount which transmittted quite a bit of vibration from the engine to the chassis and cockpit. I was able to sit at a light and see the reflection in the rear-view and side mirrors vibrate. I would guess that a solid mount would be much worse.

For me, this level of vibration might be acceptable in a track-only car but not for my daily driver so I switched back to a stock motor mount (which I'll probably have to replace again in 50K miles).