I have the TRD springs installed on my base (non GT) 2.4 and the ride has gotten really harsh lately.
I only have about 32,000 miles on my car. Im not sure whether to go back to the stock springs or replace the shocks or both. I just had a kid recently. He's about a month old.
Im seriously considering going back to stock springs because I dont want him to get all jostled around when he has to ride in the vibe.
I already bought some replacment KYB struts because I thought that somehow I blew out my oem ones in a very short time. The guys at the parts store seemed to think this was ludicruos when I told them my milage. I got the parts online but messed up and ordered KYB front struts for a 1.8 instead of 2.4 doh! I have to sell those front struts now or something. If you order them yourself make sure your getting the right ones. I think the GT would actually use the same rear springs as the awd.. but im not eniterly sure. other than that im not sure about any fancy after market struts for our 09 + vibes.