I have had these engine mounts fitted along with a solid pendulum mount after i fitted my BT, the THS being on there before didn't cope with the extra power and i had massive engine movement.
These keep things in place and is a must going above stage 2+ IMO, THS was fine upto that level of power.
Bit more noisy though so not for everyone.
These are not the same as the ones REVO got from the Stasis affair, they have been revised and are now 80% stiffer than stock, (softer than the BSH ones i think)