UPDATE
Bushes now replaced easy to do (well it was on a ramp and with air tools ect) About 10-15mins per side.
Pros and cons to fitting the solid one over the standard ones
Pros Car handles much better Corners better Feels like less roll Much more feed back from the back end.
Cons More road noise and you notice the bumps and rough roads more (could be because mines loward and on 17"wheels)
Lee
Also i have found a local supplier of the heavy duty(soild bushes) at £45 for the pair so if any one wants them and cant find them send me a pm and i'll see if i can help.
yep they do transmit a tad more bumpiness through but they are much better for feel when driving the car hard
or even normal driving you can notice the difference!!
All in all tho a worthwhile upgrade would you say???
Definately and like you say it gives so much more feeling from the rear now. I'd recomend them to everyone who drives hard.
thats good to hear!! guess i have the best of both worlds tho got poly bushes with very small void holes to allow a bit of give for noise control and never had a problem with it!!! 
On a recent visit to wim the car was found to have a broken rear spring, what was thought to be the first inch turned out to be the whole bottom helix. So if 2 new springs dont fix the wayward rear end, ill be looking into the bushes, or may well do anyway, but an increase in road noise will annoy me.
So, question is which of the firmer bushes is the quietest? Difficult to tell without a back to back comparison i guess? Thanks for the info though guys, very usefull. Cheers.