always used them in the past on my rs turbos and cosworths and not a single problem with them

i now have superflex in mine from burton power and urethane main beam ones

the difference is noticeable by a lot in quality, but thats what you pay for, my superflex inserts are 3-4 times thicker than the deflex ones and the bush is more quality of look

but as i said ive never had problems with the cheap ones, good a for a road car but thats it, any track days id say go better

and the urenthane ones are the bolox if you want a good quality bush for good money