I realise this is an old thread but just changed the tyres on our Mazda 3 and they have transformed the car. Previously on Bridgestone and now switched to Yokohama. These are the Blue Earth ones and are noticeably better in the wet but, more importantly, are so much quieter. Long journeys are much more relaxed as a result and even the concrete sections of the M25 are bearable. Fully recommend them.

If you had the Bridgestone ER30s on your Mazda3 (it may depend upon which version you have, mk1 like mine, mk2 or mk3 [unlikely as all new ones are shod on Toyo Energy somethings]), then almost anything would be an improvement - as you'll see from the very poor reviews of that tyre on tyrereview.co.uk, they were noisy and very hard riding as well as poor in the wet. Mine were terrible for the last couple of years' use and felt like driving on flat tyres on rougher surfaces such as gravel-laid roads (horrible droning noise from the tyres) and had a couple of VERY hairy moments in the wet.

I switched about 5 years ago (the ER30s on mine were 6.5 years old [OEM from new] at the time but still had plenty of tread left, below ave. annual mileage) to Dunlop SP Sport FastResponse and they've been fine for the 20k+ miles or so I've done on them. I think Bridgestone went through a poor period during the mid 2000s to ealry 2010s as regards how well their mainstream products were regarded, but seem to have improved somewhat recently, though still, by their reviews scores behind their brand rivals.