I may be wrong Dan but from previous posts on here the poly RTABs are bigger and you cant run with the turner limiter kit.
i had powerflex bushes and OEM were put back in when Murketts replaced some of the rear suspension under warranty, unfortunately they didnt last a year so now they are fitting the limiter kit for me, I wont be able to claim on warranty if the RTABs go again but even Murketts say they make a worthwhile difference, I will let you know