Do Powerflex suspension bushes give any real benefit are they worth the investment?

If anyone has any experience with these I would appreciate your views in real term as I've read the website info but not had any real feedback from people who have used them.

Thanks,

Mahbs

i found they tightened up the front end a bit...

cars pretty stiff and it did help reduce the play over bumps, etc... altho I'm sure the original ones were probably well past it