just what the title says... what's your opinion?

my fronts seem to be ok but the rears seem not to be. i got a G coupe with GF-210s and i was gonna get 350Z tokico HPs just for the rears.

 

Don't do it. If you are going to be replacing just the fronts or rears only, stick with OEM. You will feel a difference in handling and it will feel a lot worse than stock.

This is due to the fact that the Tokico HP's shocks have higher dampening than the OEM shocks. I know because I rolled around with stock front struts and Tokico HP rear shocks. It stiffened up the rear so much that the front felt VERY soft and rolled like crazy when taking turns. And when you brake hard the front nose will dive considerably more. I hated the setup and went ahead and got the Tokico HP struts installed a few weeks later, and it handled terrific. My recommendation is to do both the struts and shocks at the same time, or else stick with OEM replacements.

By the way, I use the G35 Tokico HP struts and shocks and not the 350Z ones. Either way you go, the HP's rock!

 

Springs and shocks are matched to wheel base length to TUNE the system to a specific highway speed. To avoid pitching and undulations due to time delay from front to rear.
The front hits a bump [or dip] at 60 mph [88ft/sec] with 112" ..........the rear sees the same disturbance in 1/10 of a second or 10 Hertz.

The rare rules of thumb in designing shocks to match springs to be found in suspension textbooks and software.
http://www.gmecca.com/byorc/designsoftwarecontent.html

http://www.eng-tips.com/faqs.cfm?fid=768