I've not read all the way through this thread so I might be repeating what's been posted but just to add to the feedback on powerflex engine mounts, I've been running mine for about 6 months now and love em! Don't get me wrong if you want to feel like your in an expensive tourer you'll hate them but if you can put up with an aftermarket exhaust you'll be fine. If you adjust your idle you can cancel out the vibrations on idle it only really gives a bit of a judder when pulling away but I do have a paddle clutch so that's expected. I drive my car daily an it's fine.
My stock ones were done so I noticed a huge difference and on the dyno it actually showed a 3hp gain between the fly and the wheels which for 60 quid is pretty dam good.
Alan